© 1999 by Colin Carson
I have thought about writing this for more than a year now. It all began when I converted an old Mauser mismatched rifle into a little sporter for deer hunting with up here in Eastern Ontario.
The weather during hunting season here can be just about anything you might imagine. It might be a beautiful fall day in the mid fifties one day, or it could be minus 10 the next. It also could be very dry in the cold or very damp. The woods are also very thick up here and a hunting rifle with a fancy walnut stock will surely show its age quickly after a week being hauled through such terrain. It just made sense to put this rifle into a synthetic stock. It would be inherently more resistant to changes in point of impact due to temperature and humidity fluctuations and it would sustain more abuse without showing the scars. I went shopping for a stock.
Synthetic replacement stocks are very popular nowadays. I had plenty to choose from. But I soon found out that there are no bargains to be had in this market. It is a simple case of "you get what you pay for". At the low end of the price scale are the plastic stocks. These may be reasonably priced but in actual fact they may not really give you any advantages over a similarly priced wood stock. They allow too much flex to ever hope to get consistent bedding with and they just didn't feel like they could stand up for long in the tough going. On the upper end of the price scale are beautifully made stocks that are obviously well made. Once you do the final glass bedding in these stocks, (even with those fancy aluminum bedding blocked
stocks, final glass bedding would be needed to mate to your particular action for best results) you would surely have a fine stock that would last for years.
Why didn't I just buy one of those? Well, besides being a cheap old bugger, I couldn't find the stock configuration in these models that I really wanted. I had a mental image of the shape and design I wanted. I also wanted a certain recoil pad, a certain length of pull and a few other little things that can be modified easily with a wood stock but not so easily with a off the shelf synthetic. If the wrist of a wood stock feels too thick, it can easily be shaped to the users taste. If the pull is too long with a wood stock, it is a simple job to cut it back and reinstall the recoil pad. This is not the case with the synthetics. That is when I decided that either I lay out a VERY large amount of money for a custom made synthetic or make one myself. Like I said before, I'm a cheap old bugger so the option to do it myself was easy to make. Besides, when this method is done right, you can have the same quality of stock as these top quality models for the same price as the low end plastic ones!
Make no mistake. This is not a weekend project. It will require a few weeks probably. It requires some skills in working with fiberglass resins, woodworking skills, painting skills and a great deal of thought in the planning and design stages in order to end up with a finished project you will be happy with. The number one prerequisite to have for this project is patience. I will first give you a general "run down" on the project and its materials and then later show you a step by step "run down" on a slightly different stock. The descriptions may be a little difficult to understand at first, but when you begin construction on your own, I'm sure you will start to understand better what I am talking about. Every project will be slightly different but the main construction points are always the same. I think that by getting a general idea from these notes and studying my demonstration section you will be ready to start. Then you will fully understand the "step by steps" when you reread the notes as you progress through your own project.
The heart and soul of your finished product is the template from which you will make your mould. This is where you can be artistic and make a stock that you want. It can be anything you want it to be. But just remember that you will have to be able to easily mould it and it must be designed in such a way so that it can be removed from your mould without destroying the mould so that you can use that mould to actually build the synthetic finished product.
The actual in-letting for the action and barrel of your rifle are the
hardest part to reproduce in a template, so why not start with an old
factory wood stock for the template. In some cases the original wood stock
can even be reused after the project if the design of your template is
not too different from the original. I have used factory stocks and simply
reshaped the fore ends and pistol grips with modeling clay in order to
get a mould of the shape I was after, and after the mould was done simply
cleaned the original stock and saved it for future use. For more radical
designs or for Military guns that may have collectible features that should
The template stock can then be shaped just the way you want it. You can use formed balsa wood pieces to add cheek rests and pistol grips. You can do the same to form a larger "beavertail" forearm. Modeling clay can also be used to fill finger grooves that you do not want reproduced (common in Military type stocks). Just always keep in mind that the final shape of the template must be such that when the mould is cast, that the template can be removed afterwards. Also remember to inlet the barrel channel for the dimensions of any replacement barrel you might be using. The template will be an exact copy of the finished synthetic stock. When the template is finished you are ready to begin construction of the mould box.
You can build the mould box from almost any scrap material you might have. The base should be strong enough to support the finished weight of the mould so that it can be easily moved without risk of the mould cracking or warping. The mould box simply reduces the amount of moulding material you use. This is to save you money so don’t spend a fortune just to slap together the mould box.
The box should be just long enough to hold the stock. It should be just wide enough that you will be able to add enough casting material for a strong mould and just high enough that you can easily work "inside" the box comfortably. Do yourself one big favor in the construction of the box though, use screws to hold it all together with. It can very handy sometimes to remove the ends of the mould box to remove a stuck template or fiberglass lay-up from the mould.
To fill the unneeded volume under and around the stock, this is what I do. Wrap the template stock in a large garbage bag and tape wrap it loosely. Then spray the wrapped template generously with WD-40. This will act as a release agent. Place the template in the mould box and support as needed so it is level. Just use some scrap pieces of 2x4 lumber for the support. Now you can use an aerosol can of expanding Urethane foam insulation to fill all the areas around the template. When the foam "filling" cures fully, you can trim the height of the foam even to your moulds parting line (explained later) and then you can remove the wrapped template.
Now you can remove the wrapping and set the template into the rough mould shape again. Inspect that you will have AT LEAST 3/4" of clearance all around the surfaces of the template for the casting material thickness. Trim the foam as needed.
OK, what's all this stuff about parting lines? The way we are making
these moulds are in 2 pieces. Top and bottom. (You can get a better idea
by looking at the pictures). We need to do it this way for a few reasons.
First is so you can remove the template from the mould
You are almost ready to cast the bottom half of the mould now. Lay the template back into the mould box. Where the action screws pass through the stock, insert dowels of the right size or even drill bits through these holes and press them into the foam core of the mould box. These will help center the template in the mould box to the exact same position every time the template is removed and reinstalled. Now have a last look at the template. You can see where the casting material will fill to all around the template and inside the in-letting. Make sure that you will be able to remove the template after the mould is set! Quite often, areas of the in-letting will be a problem. The best bet is to slightly modify the in-letting with modeling clay to eliminate these areas. These areas can be reshaped when doing the actual bedding of the rifle action.
For mould casting material, the home hobbyist has 2 good choices. Plaster of Paris and automotive plastic body filler (Bondo). For the bottom half of our mould, you will need quite a bit of material. I have used both and I must say that the body filler is a lot nicer to work with and stronger but the plaster is a lot cheaper. The plaster is also good in that it can be poured into the mould cavity to cast the mould. With the body filler, the filler must be spooned into the cavity and then the template must be pressed into the filler. For the first try at this type of project I recommend using the plaster for the bottom half of the mould. I always use the body filler for the top half to get added strength. You will probably need about 10 pounds of Plaster of Paris.
Before you begin pouring the bottom of the mould, the template must be treated with a release agent so the plaster will not adhere to the template. If your template is not going to be returned as a useable stock anymore, then paint it heavily with gloss enamel paint first. If the stock is to be saved you can skip that step. Next is to rub on a thin coating of grease (I just use automotive, general-purpose grease) everywhere on the template and in the in-letting areas. Do not leave any build up of grease in sharp corners, anywhere there is grease will not be cast properly in the mould. Even a small "lump" of grease will show up in the mould. Remember that the mould will only be as smooth as the template and the final lay-up in fiberglass will only be as smooth as the mould was! NOW you are ready to pour the bottom half of the mould.
You can pour the mould in stages. Start by pouring about an inch of syrupy
plaster mix into the bottom of the mould. Now you can guide the template
over the alignment dowels, down into the mould box. Press the template
down into the plaster only far enough to get a good casting of the bottom
surface of the template. You want to have sufficient plaster thickness
to give strength to that bottom surface of the mould. The
Now you must wait for the plaster to fully cure. Find a warm dry place to let it cure. If it is very humid, a fan or even a heat lamp could be used to help things along. Give it at least 24 hours before trying to remove the template. You want to make sure you can remove the template from the mould before casting the magazine well and other parts of the lower in-letting. If you did the design stage properly and the release agent application properly, then it should take no more than a gentle tap here and there for the template to pull out of the mould. After you know it can be removed you can drop it back in! NOW you can cast the magazine well.
In order to get a good bond between the previously cast bottom surface and the rest of the not as yet cast magazine well, I drill 3, 1/4"holes in the previously cast bottom of the magazine well. Now you can just pour in the small amount of plaster needed to fill the magazine well to JUST BELOW the upper part of the in-letting. If you are at all unsure that you can easily remove the template after this step then wait another 24 hours and then try again. Otherwise you can begin to cast the top half of your mould almost right away.
The top section will be cast with body filler. If you have never used this stuff, you might want to practice a bit. It sets up fast and if you try and spread it or "work" it after it begins to set, you will not get good results. Only mix up about 2 golf ball sized "blobs" at a time. You won't have time to work with more at one time.
Before you begin, have on hand some thin strips of scrap wood, cut up to press into the casting at critical points to add a "spine" along the length of the casting. I like to have one strip that can be laid along the whole length plus a few shorter ones to place along the sides of the butt stock. These will assure that you can handle this casting without fear of it cracking or bending.
Make sure you have applied a heavy coating of grease to the top surfaces
of the mould box plaster and you can begin. I sometimes also use a layer
of waxed paper along the length of this surface. Work in sections and
use a putty knife to press the wet body filler into the contours of the
templates top surfaces. You can build up the casting in layers. When the
whole template has been covered with at least 1/2" of body filler,
add the "spine" to the cast and spread more body filler over
the spine to cast it right into the upper mould section. Let
When you go to remove the casting from the template, you may want to remove the ends of the mould box to make it easier. You wont need these end pieces any more anyway. You can also now remove the template from the bottom of the mould now. You are done with it as well now.
Quite often you will need to do some minor touch-ups to the mould sections. I usually just use a pre-mixed joint filler compound (sold in tubes in the paint department of any building supply store) that is usually used to patch nail holes in walls before painting. This stuff works great to fill any minor imperfections in the mould halves. Again, remember that the finished mould will be an exact duplicate of your finished product. Try and get it as perfect as possible.
This is often a good time to let the mould sit for a few days to make sure that it is fully dry. The next step is to prime and paint the mould sections, so you want to make sure the mould is fully cured for maximum paint adhesion.
The upper half of the mould that was done with body filler can be simply painted with any spray enamel. The lower plaster half may not hold paint quite as easily. I find that a latex based primer sealer works very well. After it is dry I use the same gloss enamel spray as the top half. The next step is to apply a good release agent to the mould halves.
I have tried lots of different release agents. I have used paste wax, grease and even specially formulated sprays that I purchased when buying my resins. I find that for the money and ease of application, that grease is still the best. You don't need much and it always works. Just the same as when applying it to your template, when greasing the mould, do not let the grease build up in any corners. A Q-Tip works wonders for this. Now you can prepare to do the fiberglass lay-up.
Fiberglass is amazing stuff. A few layers, properly laminated can be as strong as steel. It comes sold as both a cloth and a mat. The cloth is used for most of the lay-up and the mat is used to build up thickness fast in areas requiring reinforcement and also is handy for moulding around tight corners. You will need at least 2 yards of cloth and about a half yard of mat.
I start by cutting the cloth into various sized strips and squares. The biggest pieces I find manageable are approx. 6" long and 1 1/2" wide. Any larger than this and they become unmanageable. Other various sizes are used, down to small 1" x 1" pieces. The matting is usually needed for tight spots, so cut most of it into very small pieces. I find a sharp utility knife works the best to cut this stuff. Cut about 3 times more than you think you will need and you will be ready.
Each piece of glass cloth and mat must overlap with the next to build
strength. It's sort of like building a patchwork quilt. The other key
point in getting strength into fiberglass is to never allow any air
The main sections of the stock require about 3 layers of cloth for sufficient strength. The action area requires more strength. It will end up to be an almost solid mass when you are done. The butt stock area can be given a layer of matting over the cloth layers for more strength as well. I will focus more on this area in the demonstration section later.
The action area is the trickiest part to do well. You probably will have
only a small space in which to lay in
Special powdered fillers will be sold where you buy your resins. I prefer the high-strength type filler rather than the lightweight "micro-ball" fillers. Mixing this powder into your resin until you get a "peanut butter" consistency allows you to cast around tight corners easily. You can then lay on your layers of cloth over this filler layer while it is still wet to get all the needed strength. You can also use this filler to solidify the spaces left between the cloth layers between the outer wall of the stock and the magazine well.
There will also be the area where the actions recoil lug bears upon the stock. This area requires as much strength as you can give it. I have always used multiple layers of matting to build up this area and have never encountered any problems. Just make sure that the matting is fully saturated with resin and that there is no air space between each layer and you will have as much strength as you will possibly need.
The resins I use are epoxy type resins. They offer many advantages over polyester type resins. Polyesters eat away foam fillings. Later this will be a factor. Epoxy is also stronger than Polyester. Another big plus is that Epoxy does not absorb moisture. Polyester slowly will through a process called osmosis. Epoxy resins also do not give off any strong odors so you can do the work in the house without your family members complaining. All in all, even though epoxy resins cost more than the polyester, the epoxy will give you a quality job that will last forever. I have found that I always need a little more than 1 quart of resin to complete a project. You can purchase only one quart at a time if you prefer to try and do it with only one. Unfortunately, a lot of the resin gets wasted. Even by only mixing about 1 oz. At a time, I always seem to end up with more than I can use before its working time starts to run out.
I like to buy the resin made by Bondo Corporation because the resin and
its hardener are both used in 50:50 proportions. I find it easier to mix
small quantities at a time this way.
The upper half of the stock is cast in mostly the same fashion. I usually find though, that this area has more sharp corners in the top half that are hard to get the cloth and matting to press tightly into. For this reason, I like to start the top section by mixing up some more thick filler and resin mix and applying it all along the outside edges of the barrel channel and all around the action area.
Then I start doing the lay-up work in the butt stock area while the filler mix sets up to a slightly firm consistency. Now when you reach the tight corners of the action area and along the barrel channel, the cloth and matting can be pressed into the slightly cured filler mix. It is very easy this way to get a very accurate and very strong casting of the upper mould half this way. The basic lay-up is now done. Now you must let the resins fully cure before even attempting to get them out of the mould halves.
The first step before removing the lay-ups from the moulds is to trim the edges of the lay-up back to the originally cast parting lines of the mould. In doing your lay-up, you will most likely have a pretty rough edge along the sides. I use a small 2" grinding disk for this task. A Dremel tool comes in handy for this and other trimming and sanding jobs. The object here is to have your 2 mould halves fit almost perfectly together once you remove them from the moulds. It is a lot easier to know how much to trim while the halves are still sitting in the mould.
Now, if the application of the release agent was successful, the completed lay-ups can be fairly easily extracted from the moulds without damaging the moulds too badly. I am only mentioning these details because I keep all my moulds to be used again and again by my friends and myself.
Now with the 2 halves removed from the mould, you can begin to do some
final trimming so that they fit together properly. Then you can make sure
I only join just the action area together at first. The idea is to get an almost solid area here of glass and filler. Depending on your design and action type, you may want to build a small "dam" with either glass cloth or even balsa wood on either end of the action area. The plan is to overfill the action area with filler and then screw together the action to clamp the whole area down. The clamping will give proper alignment of the 2 halves of the lay-up and squeeze out the excess filler and any air pockets. The "dams" will prevent the filler from running out of the action area.
You will have to make sure not to get the rifles action stuck in the epoxy. Coat all metal parts with grease. It is also a good idea to remove the trigger mechanism of the action and fill the area of the trigger in-letting with modeling clay for this step. When everything is ready, mix up your epoxy and filler and fill the lower half of the lay-up as much as possible with the magazine assembly and any other lower metal parts in place. Join the upper half of the stock with the receiver in place and tighten all action screws fully and let the epoxy fully cure.
The next step is to epoxy the top of the barrel channel to the fore end of the stock. This is a simple matter of lifting the top half away from the bottom half slightly so you can apply a heavy coat of epoxy along each sides mating surfaces. Then use a regular woodworkers 'C' clamp at each end of the barrel channel to hold the parts in alignment until the epoxy cures. (Epoxy resin does not require any excessive clamping force. Only use enough pressure to properly align and hold together the two moulded halves).
Lastly the butt stock joints must be completed. The joints can be filled by joining both sides of the gap with fiberglass cloth from the inside of the butt stock. This easily done by first taping a small stick to your paintbrush and using some longer sticks to help press down the cloth strips. I only do one side at a time so I can lay the stock on its side to cure.
This joint can be an important part of the structural strength of the entire stock. A properly designed stock should be able to easily transfer the guns recoil forces back to the shooter. You have already made the actual action area very strong, I build up the joints along the sides of the butt stock heavily with cloth and matting as well. I believe that when these reinforced joints flow from the action area to the butt of the gun, the recoil forces are evenly transferred to the shooters shoulder rather than being absorbed by flexing in the stock. To me this should make the gun more accurate. This is just my opinion of course. I am a hobbyist, not a physicist.
To add to this concept, I will often "bridge" the space across the lower butt stock section, from the wrist area to the butt, with either glass cloth or a laminate of a balsa strip and cloth. I do this step before joining the 2 halves of the lay-up together. I show this example in the demonstration project later. The final stage of the reinforcement of the butt stock area is to add a bit more strength to the wrist of the stock. All I do for this area is to clamp the stock with the butt raised to a almost vertical position and pour a small amount of a syrupy mixture of the epoxy and filler mixture down into the wrist area to achieve a gradual "flow" from the solid action area to the butt stock areas "bridge".
By now you have yourself a fiberglass stock! Now you can practice your "bodywork" skills! Hopefully your mould was quite smooth and the lay-up went well. This stage should go quite easily but being meticulous is the key to ending up with a final product that looks professional.
I use one of those small "detail sanders" with the small triangular, stick-on sanding pads for much of this stage. I first start by quickly sanding off any major drips of resin and other easily seen high spots with 60 grit paper. Then I spray the stock with quick drying lacquer primer paint. Next I use a rubber sanding block and the 60 grit paper over the entire surface of the stock. This method shows you any low spots and any pin holes in the fiberglass that you would not see without the primer. I fill the low spots with more epoxy and filler mixture using a 1" putty knife. Then I keep priming and sanding until the stocks surface is perfect. When the only flaws left after these treatments are pinholes or minor scratches, I use automotive "Spot glazing putty" to fill these minor defects. Then I resand the whole stock again with 80 grit and finally 150 grit paper to get a smooth finished surface.
The two ends of the stock can now be prepared to be closed off. These ends are probably still quite rough looking. First I once again install the action into the stock and measure for the length of trigger pull I desire. Remember to include the added length of any recoil pad you are planning to install at this time. You may want to shop for this item at this point if you are unsure of what is available.
I then use my tablesaw to make an even miter cut to bring the butt stock to proper length. I also cut the rough fore end off at this time as well.
To minimize the hollow sound of the stock, I use more of that aerosol,
expanding urethane foam to fill the butt stock and the fore end. Once
this cures, I trim the foam flush to my miter cuts and then I "excavate"
at least 3/8" of the foam from the ends. Then I mask off the nicely
sanded ends of the stock. Then I clamp the stock in a perfectly vertical
position and fill the stock ends with another mixture of epoxy and filler.
Wrap the masking tape so that it overextends the ends by about 1/4"
so you can actually overfill the ends. This will allow for the small amount
of absorption by the foam and also allow you to perfectly block sand the
The final step before painting the stock is to do your final bedding of the rifles bedding. I won't get into all the various methods used by various action types etc. If you have taken on this project, I am certain you already know what method you will be using. I will mention though, that I have had very good success using the epoxy cement by the name of JB Weld. It cures as hard as nails and seems to adhere perfectly to the existing epoxy used in the stock construction. Once this is done, I mask off the bedded action area and prepare for final paint finishing.
This is another area of the project that is totally up to you. Maybe
you or one of your friends is an expert with an airbrush and you want
some sort of high tech scheme. I guess you could have even decided to
add coloring agents to your epoxy resin in the initial lay-up. I have
also heard that an aerosol automotive type paint called "Trunk paint"
works well. Again I will just let you in on my "secret", never
chips, never gets eaten by chemicals finish. It is sold here in Canada
by a chain of automotive supply stores called Canadian Tire. The product
is an aerosol, spray on pick-up truck, bedliner coating. I really don't
know if it is a urethane or an epoxy based product. All I know is that
it gives a satin gloss, black, pebble grain finish that does not seem
to be affected by anything. I imagine the same product, under various
name brands can be found at other auto supply stores anywhere in North
I hope that the following demonstration project will help with any design
ideas you might have. I used all of the techniques on the following project
that I have tried to explain in the preceding section. The
This laminated stock is strictly for target use so weight was not a concern but the finished product is still lighter than a similarly constructed wood stock. It was constructed for maximum strength and rigidity. Hopefully my pictures, along with my text, will fully prepare you to construct your own project.
I also had an old Mauser stock that was severely damaged. It had a bad crack through the recoil bolt area. It also was cracked in a few places in the butt stock area. It was a perfect candidate to become the basis of a template. I degreased the old stock and cut it to length. Then I picked up a supply of balsa wood sheets and blocks and a supply of automotive body filler.
Using the above picture for my inspiration, I glued a roughly shaped
pistol grip to the butt. Then I added 3/8" balsa sheeting to the
fore end of the stock for the rough-in of the beavertail fore end. I used
a rough rasp to further shape the stock and then used the body filler
to help blend in the modifications. I also used a rasp as well as a sheet
of coarse sandpaper, wrapped around a suitably sized dowel, to route out
the barrel channel to the dimensions needed for the barrel I ordered for
I also used a small strip of balsa to raise the comb height of the stock. Finally I covered any blemishes and defects if the stock with more body filler and filed, sanded and smoothed until I was happy with the template.
I always kept in mind that the lower sections of the stock could not be any wider than the top sections so that I would be able to cast a mould of the template without having problems extracting it later. When I was satisfied with the template, I primered and painted it with a high gloss finish and wiped it down with the grease I use as a release agent.
The next step was to construct the mould box. As I explained in the first
section, this was made with a strong base to support the mould and all
side and end pieces were fastened with screws so that I could disassemble
the box to help access the casting area for when I did the lay-up later.
It's 'Glass' Time.
Now you can prepare for the actual lay-up work. All cloth and matting is cut to proper sizes. You should also have a large amount of disposable mixing cups, small paintbrushes and Popsicle sticks on hand. Acetone is recommended for cleaning up epoxy resins but I find that (cheaper) Lacquer thinner does a good job. Make sure you have applied the release agent and you can begin.
Here I have applied the initial layers of resin and cloth to the mould. Then while it was still 'wet', I laid in the balsa reinforcements and again cover them with glass and resin. Note how I used pieces of Popsicle sticks to keep the balsa strips pressed hard to the outer contours of the lay-up. I worked from the front to the back, covering all sides as I went. This insures that the resin is still 'wet' when you add more layers or move from the bottom to the sides. This increases the strength of the project. Try to set aside about 5 or 6 hours before starting the lay-up on the bottom half so you will have lots of time to complete the whole section while the resin is still fairly uncured.
I continued on to the rear of the stock using cloth and mat as detailed in the text section. I added the balsa insert to the pistol grip hollow after laying in the glass there and then filled the small gaps around the insert and the outer walls with a filler mix of resin.
Remember also to build up the area where the recoil lug of the action bears against with fully saturated matting. Build the area in layers making sure no air bubbles are trapped. Also remember to build a bit more strength into the butt stock. Either use more matting and/or use a balsa or glass 'divider' in this area.
Now the upper half of the mould can be glassed. As I said in the text section, I start by applying a thick resin and filler mix along all the sharper edges of this part of the mould. Make it thick enough that it does not 'run'. Now while this mix is still uncured you can apply your cloth and mat on top of the filler mix. Just make sure not to have air bubbles between the layer of filler mix and the cloth layers. Continue to work in sections as you did for the bottom half of the mould.
When the bottom half of the mould is cured, you can insert either balsa wood or even cardboard 'dams' in front and to the immediate rear of the action area.
Then pour in a fairly thick resin and filler mixture to fill most of the spaces between the magazine well and the outer walls. Remember that you want the action area to be solid.
After all parts have been fully laid in and cured, you can use a small grinding disk to trim any glass material that extends from the edges of the mould halves. Then you can remove the halves from their moulds.
Here are the moulded halves, fresh from being removed from the mould box. Next, the 2 halves being checked for initial fit.
Now you can trim the 2 halves and clean up the inletting until the action fits properly in the 'new' stock and the 2 halves mate together properly. Action screw holes might need to be redrilled and other small trimming done. As I said before, a Dremel tool does a great job for this work.
All the joints between the 2 halves should be quite close but along the section of the fore stock where the 2 halves meet, make sure that there is a 'fillet' type gap left to make a stronger glue joint later. Refer back to the text section for the needed preparations to join the 2 halves and when you have triple checked everything, proceed.
After the action section, then the fore end section and finally the butt stock section are joined and cured, the 'body work' can begin.
Here is the stock with the first rough sanding done and the first coat of primer applied. The primer REALLY helps to show the small flaws that you will need to tend to.
While you work on the exterior, you can also build up the wrist area of the stock as per the text section and add the expanding foam to the hollow fore end and butt stock areas. I do not trim the rough ends of the butt or fore end until the 'body work' is almost complete.
Here is the detail of the Balsa "bridge" in the butt stock. It runs from the action / wrist area, right to the butt pad area.
Always sand with a block to show low spots. Use a fairly stiff putty knife or spatula to fill low spots with more filler and resin mix. Use the detail sander I mentioned in the text section, it sure helps save your elbows for this stage. Patience and multiple sessions of priming and then re-sanding to show the low spots is the key here. When only a few pinholes are evident in the stock, you can touch them up with automotive "spot and glazing putty".
Now you can measure your length of pull you desire, (This might be a good time to buy the recoil pad or butt plate you want to use so its length can be factored in) so you can cut off the rough ends of your stock at the butt and fore ends. Use a tablesaw to get the angle of the cut the way you want it and to get an accurate and straight cut.
After cutting the ends flush, "excavate" about 3/8" of the foam filling from the ends to allow room to fill these ends with resin.
Don't forget to wrap the outside of the stock ends with some wide (2") masking tape. I let the tape actually extend out over the cut ends. The tape will protect the nicely sanded stock from drips of resin and also allow you to slightly overfill the cavity. Remember, you will need this overfilling because the resin will slowly absorb into the small pinholes of the foam before it cures. You want to end up (with some minor block sanding) with perfectly flush ends.
Now you can stand the stock upright and fill one end at a time (obviously)
with more resin and filler mix.
Now you can do the final bedding of the action and any other assembly work of the action and barrel. When that is done you can apply the final finish.
You can choose to finish the stock however you want but I really prefer my "secret" spray on bedliner material. The pebble like finish and low gloss make it ideal for a rifle stock finish. Try and find the product and give it a try!
Well, you have finished your stock now. If you took your time, you have something that would cost hundreds of dollars to buy and it will last forever. Please send me pictures of your projects. I would really like to see this technique develop within the circle of home hobbyists and amateur gunsmiths. This project shoots 1/2 MOA groups all day in any weather. Just remember, this booklet is only a guideline, make your stock the way you want it. Just take your time and PLAN, PLAN, PLAN.
I will leave you now with some finished projects pictures.