Gunsmithing Homemade Fiberglass Stocks?

Bryan27

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Minuteman
Jul 31, 2007
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I've been doing some reading up on fiberglassing and making fiberglass molds, something I've never done before but doesn't look like something that would be outside my abilities. There's a lot of information out there about doing fiberglass work and making molds, but nothing I can find shows anything about making stocks with fiberglass. Anyone here ever made their own mold? I'd be interested in hearing some ideas about mold design, techniques and different types of fill used to make them solid. With all these guys on here lately turning out these badass homemade stocks, surely someone's done some fiberglass.
 
Re: Homemade Fiberglass Stocks?

Adding wood, fiberglass/fillers to modify/change the shape of an existing stock is a completely different animal than making a female mold, and hand-laying fiberglass like McMillan does.

Modifying an existing stock like above is certainly easier- and far more practical, than making a mold for a one-off stock. But, it's not a "fiberglass stock".
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wannashootit</div><div class="ubbcode-body">Adding wood, fiberglass/fillers to modify/change the shape of an existing stock is a completely different animal than making a female mold, and hand-laying fiberglass like McMillan does.

Modifying an existing stock like above is certainly easier- and far more practical, than making a mold for a one-off stock. But, it's not a "fiberglass stock".</div></div>

Yeah, I agree with that. Looks like the first part of that thread is about making a plug out of a wooden stock using body fillers. The middle of the thread he used the plug to make a mold and started molding around an existing stock. The end of the thread is about people trying to get their money back after getting ripped off...

Neat idea, but I wouldn't consider it as a "fiberglass" stock either, it's more of a hybrid stock. I guess it'd be a good method to get around having to inlet.

I'm still curious about how the lay up schedule and fill schedule would go with a true fiberglass beyond the obvious. Also curious on what would be a good fill material or materials. Filling a stock with straight epoxy would make it heavy, filling with a mix of epoxy and talc/wood/microballoons/shredded glass/lead shot/airsoft pellets/eurathane foam or whatever you can think of you can adjust the density of the fill, thus the weight of the stock. You'd want something that wouldn't be effected by the heat of the barrel in the fore end, something that would be stable and rigid in the action area through the grip and something rigid and lightweight in the buttstock area. Just thought it would be interesting what some people on here could brainstorm up as far as mold design and fill schedule.
 
Re: Homemade Fiberglass Stocks?

Bryan,

I don't mean to discourage you, but your chances of finding much help in the area of composite stock construction are pretty slim. People like Tom Manners and the McMillans have spent mucho time and money developing their products and you can't blame them for not offering info. That being said, have at it! If they can do it so can you with the proper R&D. I have been working on several myself and am at the mold stage currently on several designs with production beginning sometime this summer. At the risk of sounding selfish or arrogant, I will say that I am no more willing to share specifics than Tom Manners or the McMillans, however I will give some things in general to consider. Resins...there are literaly hundreds of blenders blending epoxies for all sorts of uses. Using a resin with a high Tg value is a must in my opinion. You certainly don't want your stock turning to jelly in the trunk of a squad car in Arizona in July. This requires a ramped post cure schedule specific to each blend. Inletting...need I say more? Fills...this is something you will just have to experiment with. Who knows Bryan, you may discover a much better fill on your own. The list goes on. As I'm sure you are aware, this ain't no weekend project!
It sounds like you may have a good general knowledge of composites so just keep looking and experimenting, you'll find the answers!

Jon
 
Re: Homemade Fiberglass Stocks?

I've been brainstorming ideas on this myself. I was considering using an existing stock for prototyping and plug construction, but, you are confined somewhat by the original stock design. I was thinking a balsa or styrofoam plug would be a better option for the prototype. PM me and we can brainstorm or pool resources.
 
Re: Homemade Fiberglass Stocks?

Actually, starting with an existing wood stock to fit the action of choice is a good idea. I've done a couple myself using a like method. If you are handy at wood working you can add and subtract wherever leaving your inletting in tact. Having access to a table saw, a band saw, a drill press, a router, and a good variety of tooling is almost a must to achieve symmetry and trueness. With a little ingenuity and creativity some straight grained poplar and epoxy the sky is the limit. After shaping, if you have engineered strength and stiffness back in you can put it all back together and shoot it! Then you can fill up your inletting, make a mold and figure out how to in-lett your final pieces all over again.
I'm one of the old dudes who has learned during a lifetime of developing craftsman skills that searching the heart and mind of a master of any given trade is crucial to excellence, and to choose who you study wisely! Don't just copy them, expand your mind and your skill from observing their excellence.

Jon

I don't claim to be very smart...just experienced.
 
Re: Homemade Fiberglass Stocks?

A true, molded FG stock just isn't practical for a "one-off".
That's why custom, high-dollar yachts are cold-molded. Mold construction just isn't economically feasible for one stock or two.

Why not just use wood? I just finished this one, simple to do (except for the inletting :))

I'm still on the fence with the purple...please...my son made me do it
smile.gif
... it may become a camo job.

IMAG0699.jpg
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jonwatts</div><div class="ubbcode-body">Bryan,

I don't mean to discourage you, but your chances of finding much help in the area of composite stock construction are pretty slim. People like Tom Manners and the McMillans have spent mucho time and money developing their products and you can't blame them for not offering info. That being said, have at it! If they can do it so can you with the proper R&D. I have been working on several myself and am at the mold stage currently on several designs with production beginning sometime this summer. At the risk of sounding selfish or arrogant, I will say that I am no more willing to share specifics than Tom Manners or the McMillans, however I will give some things in general to consider. Resins...there are literaly hundreds of blenders blending epoxies for all sorts of uses. Using a resin with a high Tg value is a must in my opinion. You certainly don't want your stock turning to jelly in the trunk of a squad car in Arizona in July. This requires a ramped post cure schedule specific to each blend. Inletting...need I say more? Fills...this is something you will just have to experiment with. Who knows Bryan, you may discover a much better fill on your own. The list goes on. As I'm sure you are aware, this ain't no weekend project!
It sounds like you may have a good general knowledge of composites so just keep looking and experimenting, you'll find the answers!

Jon</div></div>

Yeah, I understand where your rational from a business standpoint, but never really expected Manners or McMillan to chime in with any of their industry secrets. With all the guys on here that are putting out impressive gunsmithing work I figured there might be a couple who might have tackled such a project before. One thing I have learned through researching this is that it isn't an economical alternative to buying a stock from one of the pro's. I imagine that getting a non-inletted plug built to the point that it can be used to make a mold will take 50+ hours of work, barring any mistakes. Making a mold off of that plug would take several days to weeks to complete. Then experimenting with different laminates and procedures and fills would be an ongoing process. Being realistic about it, it would take someone doing it as a hobby in their garage several months of experimentation to get to the point that they could build a usable stock that has a predictable weight and balance to it. One thing I certainly need to do is learn more about the different materials and resins, it's one of those "I don't know how much I don't know" things when it comes to the actual materials involved in fiberglass work. You can apply logic, design and your own problem solving abilities to building a plug and mold, the materials are just something that are going to have to be learned. For instance, I don't even know what Tg is! I have a lot to learn...

One of the reasons I started this thread was to bounce ideas back and forth. One thing I've noticed over the few years I've been on the hide is that when people in this section show their work and the thought process behind it, everyone benefits from it. Since STR, 300, wmroscoe, C.Dixon and others have done build threads and how-to's everyone else who pays attention has been able to take their work to another level. On another note, the guys that have posted their work are the ones I would send work to as I've seen their attention to detail and they are giving back to the shooting community by spreading knowledge, hard earned knowledge, freely.

As far as the tools go, I have access to pretty much any kind of woodworking tool you can dream up. Table saws, band saws, scroll saws, routers, shapers, jointers, planers, sanders, lathes a pile of clamps and a treasure chest full of hand tools. When my grandpa passed away, he left a 3 car garage full of woodworking tools from a lifetime of building and repairing furniture, two houses down from me.
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wannashootit</div><div class="ubbcode-body">A true, molded FG stock just isn't practical for a "one-off".
That's why custom, high-dollar yachts are cold-molded. Mold construction just isn't economically feasible for one stock or two.

Why not just use wood? I just finished this one, simple to do (except for the inletting :))

I'm still on the fence with the purple...please...my son made me do it
smile.gif
... it may become a camo job.

IMAG0699.jpg
</div></div>

The short, one word answer would be the challenge. I've already come to the conclusion that it wouldn't make economic sense to build a plug, build a mold, go through the long learning process of how-to for the sake of building one stock. Since I haven't ever made a stock before, wood is what I will experiment with as it isn't a big loss if it's something that will be better served in the landfill than on the range. That, and I have experience, tools and equipment working with wood. From a personal satisfaction standpoint, I think that going from wood to fiberglass would get me out of my comfort zone and be more fulfilling, if I don't fall flat on my face!
 
Re: Homemade Fiberglass Stocks?

Tg stands for Glass Transition Temperature. It basicly means that at a given temperature the cured epoxy starts to soften, loosing its strength characteristics. Epoxies with a higher Tg value of say 250 degrees, will maintain its strength up to that temp. Higher Tg value epoxies require a post cure in a oven up to its Tg value. Temperature must be slowly ramped up to its max Tg value, held there for a pre-determined time, then slowly ramped down to room temp. Higher Tg value epoxies must be post cured to complete the chemical cross linking process to obtain its maximum properties. This needs to be done for the mold and the part. Standard room temp epoxies will begin to soften at 120 to 140 degrees...not high enough for me.
If your quest is to just build a stock or two for yourself, room temp epoxies might work OK for but I wouldn't consider them for resale.
Iv'e done many projects in my lifetime that just couldn't be justified financially, spending far more than I ever should have, but never did I regret the education I received in the end.

Jon
 
Re: Homemade Fiberglass Stocks?

In addition, don't worry about falling on your face, just read and take to heart the following quote from B.C. Forbes.

"History has demonstrated that the most notable winners usually encountered heart-breaking obstacles before they triumphed. They won because they refused to become discouraged by their defeats."

Are we all going to invent the next light bulb? Nope...but this works in the little as well as the big things in our life.

Have a good day all!

Jon
 
Re: Homemade Fiberglass Stocks?

Maybe carve your stock from high-density styrofoam (as a male mold), and use the lost-foam method of molding to make a female mold from it that could be used for hand layup?

Sounds like an interesting project, and as you say, for the hell of it...

I'd be interested in knowing how McMillan glasses the joint of the two stock halves, and hides it- knowing that their camo patterns are hand-painted into the molds with gelcoat before layup.

Using lost foam would make the stock carving really easy. Wonder if anyone has ever done it?
 
Re: Homemade Fiberglass Stocks?

I made one in the past for a M1A. Inletting for a semi-auto is a bitch. Probably the hardest composite project I worked on.

There are multiple ways you can go about making a fiberglass stock. You can carve out foam and wrap fiberglass around it. Doesn't work all that well and there's a lot of finish work to do.

Alternative, the better but longer way to do it, is to make a plug and pull molds off the plug. The layup schedule is dependent on what material you use and how stiff you want it. As far the the fill material, non-structural areas can be filled with expanding foam. The rest can be a mixture of epoxy and chop strands along with microballons.

I don't know what McMillan's processes are, but there a multiple ways to join two halves together. Once you lay up the shell, trim to the edge of the mold and glue the two sides together with a mixture of epoxy and cotton flox with the mold assembled together. You can also tape up the seam from the inside depending on the shape. Or you can lay up one side long and insert an air bladder.

Composite work is all trial and error. There's really no good way to learn other than by screwing up.

I have a stock I need to build for a friend of mine, maybe I need to start documenting it.
 
Re: Homemade Fiberglass Stocks?

As far as finding more information about building with composites, there's actually a wealth of information out there, just not in the gun industries.

I work in aerospace and have picked up a lot of info from our composite guy at work. I've also picked up a lot of good techniques from the RC airplane groups and home-built planes.
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Retoocs</div><div class="ubbcode-body">I made one in the past for a M1A. Inletting for a semi-auto is a bitch. Probably the hardest composite project I worked on.

There are multiple ways you can go about making a fiberglass stock. You can carve out foam and wrap fiberglass around it. Doesn't work all that well and there's a lot of finish work to do.

Alternative, the better but longer way to do it, is to make a plug and pull molds off the plug. The layup schedule is dependent on what material you use and how stiff you want it. As far the the fill material, non-structural areas can be filled with expanding foam. The rest can be a mixture of epoxy and chop strands along with microballons.

I don't know what McMillan's processes are, but there a multiple ways to join two halves together. Once you lay up the shell, trim to the edge of the mold and glue the two sides together with a mixture of epoxy and cotton flox with the mold assembled together. You can also tape up the seam from the inside depending on the shape. Or you can lay up one side long and insert an air bladder.

Composite work is all trial and error. There's really no good way to learn other than by screwing up.

I have a stock I need to build for a friend of mine, maybe I need to start documenting it. </div></div>

Retoocs,

Sorry it's taken so long to reply, the week I started this thread I was notified on a friday afternoon that I am being transferred across the country and I was to report on the following tuesday! So it's been a hectic month and a half! But I did read your response and it sparked a few ideas and the air bladder idea is intriguing to me, some of the same benefits of vacuum bagging but applicable to the shape of a 1 peice stock. Not a whole lot on the web about inflatable bladder molding, most of what I find on a google search has to do with flag pole construction. The video's I've found involved RC airplane fuselages, which is a great comparison to a rifle stock, a stock would likely be an easier shape I'd think because not all sides would need to be closed off like the butt end and the top line where the action and barrel channel will be, that would give access for applying filler later. I am a big fan of the idea of using a bladder, mostly because I haven't come up with a better idea to join the halves than in a joined mold and under pressure. That would alleviate the issue of having the halves match up perfectly and having a "cold" line in the mold, not that a cold line would matter once the fill is applied but it seems like a better way to do it. I'd love to see what you come up with for your friends stock, if you decide to document it I'd enjoy the hell out of watching!
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jonwatts</div><div class="ubbcode-body">Tg stands for Glass Transition Temperature. It basicly means that at a given temperature the cured epoxy starts to soften, loosing its strength characteristics. Epoxies with a higher Tg value of say 250 degrees, will maintain its strength up to that temp. Higher Tg value epoxies require a post cure in a oven up to its Tg value. Temperature must be slowly ramped up to its max Tg value, held there for a pre-determined time, then slowly ramped down to room temp. Higher Tg value epoxies must be post cured to complete the chemical cross linking process to obtain its maximum properties. This needs to be done for the mold and the part. Standard room temp epoxies will begin to soften at 120 to 140 degrees...not high enough for me.
If your quest is to just build a stock or two for yourself, room temp epoxies might work OK for but I wouldn't consider them for resale.
Iv'e done many projects in my lifetime that just couldn't be justified financially, spending far more than I ever should have, but never did I regret the education I received in the end.

Jon </div></div>

Epoxy by definition as a thermoset doesn't have a Tg, it doesn't melt it combusts, Tgs only apply to thermoplastics. If you have soft epoxy at any elevated temp it means you're not doing it right and that you didn't cure it properly, something you don't need an oven for. You can get UV catalysts, you just have to be careful when you put it out in the sun if you don't use a UV lamp so that it doesn't get too hot and start to burn. If you want to make a budget stock just to see if it's something you want to try, you could experiment with UV epoxy and E cloth fiberglass. Make a mold out of wood and line it with wax paper. It's going to be really fucked and require some machining but it could be done to get some practice, as the complex shape is going to require a little bit of experience with doing lay ups. You could get surfboard foam filler and use roving to make the butt stock area, since the shape is going to be tricky to do with cloth without cutting out a lot of the continuity of the fibers. I'd be interesting in creating a mock-up once I get out of school for the summer if you'd be interested.
 
Re: Homemade Fiberglass Stocks?

rideHPD,

In response to your reply concerning Tg values. I respectfully disagree that they are only used in the thermoplastics industry. I am neither a scientist nor a chemist and only use composites for my work so I am only self educated on the subject. If you do some research you will find that all the epoxy blenders that blend epoxies to withstand elevated temps use a Tg value to assist in choosing a blend for the application. Not all epoxies are created equal. You are incorrect in stating ovens are not used to cure epoxies. They are widely used and are quite commonplace in composite structure manufacturing, from the home shop to the aerospace industry. After working with composites for several years I only have practical experience and as I stated earlier I have no formal education regarding the subject matter, but much of your info is way out in left field. Most of what you have stated is either incorrect or totally impractical. Making a mold out of wood using wax paper as a release? Come on!

Respectfully,
Jon
 
Re: Homemade Fiberglass Stocks?

I respect where you're coming from, and I understand what you're saying. My studies are leading me to become a composites engineer. Everyone in industry would do a two stage cure for epoxy, typically if vacuum bagging you apply the vacuum then heat to 120C for about an hour, maybe 2, then apply pressure to about 4-5ksi and raise the temperature to 200c and leave overnight. The second part of the cure stage is to get the catalyst to be able to diffuse and react with the parts of the matrix that haven't cured yet. A Tg is a rough temperature that marks the area where a solidified part of the material will start to soften and flow like a viscous liquid, before completely melting at the melting point. This applies to thermoplastics because you can heat them, form them and cool them into their final position over and over again. You can't do that with a thermoset; once you raise the temperature of epoxy to the range where you say it softens the irreversible curing continues until you have fully cured part that can't be melted. Upon raising the temperature more the epoxy will burn, leaving behind the fibers, which is actually a method to measure fiber volume content.

That said, you can still build an epoxy composite that can withstand those temperatures with UV catalyst if you take some time to figure out how to get a full cure without screwing up the part. It takes a little bit of messing around as the way the light propagates through the part cause a weird variation in curing that you really can't treat against. I know the wood mold sounds really ridiculous, but in reality, trying to make a mold for a stock without machining one is next to impossible. If you have a mill you can do it, but I've made molds at home for ridiculous shapes that came out workable. The wax paper takes out inconsistencies in the wood when shaping. It isn't ideal but it's really cheap, and if you've never worked with hand lying glass reinforced polymer composites you're probably going to screw the first one up. Then you can figure out how to make it work for the real thing once you understand what you're getting yourself into.
 
Re: Homemade Fiberglass Stocks?

Even without translation, bly's excellent series of pictures has shown a very good practical application of mold and part making. I do not make both sides of the mold as he did, but instead make a "parting board" and use the plug in its whole form to construct both sides of the mold. You obviously know what you are doing bly, I just choose to do it a little different. If ya'll want to learn how its done, study his pictures!


Jon
 
Re: Homemade Fiberglass Stocks?

Wax paper on wood, really? Pam? You gotta be kidding. In all my years working with composites, I have to say, I never heard of anyone using wax paper or pam for mold releases. Wax paper is just about the worst thing you can use to make a mold off of.
 
Re: Homemade Fiberglass Stocks?

I think that by the time you're done, you'll better understand what you're actually paying for with a professionally manufactured FG stock, and those prices won't be looking so unaffordable.

I have considered long and hard just what's involved in making any kind of a one-off stock, and also seen some relatively well done examples. I have some skills and resources for working wood, and I can do fiberglass marine repairs. I'm not a gutless wimp, but I still haven't tried my hand at stock making.

Greg
 
Re: Homemade Fiberglass Stocks?

I just finished making a stock out of epoxy/fiberglass cloth. It took about a month to finish working on it after work and on weekends. After spending about $200 in material and all that time It would have been easier to buy a manners.
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">I think that by the time you're done, you'll better understand what you're actually paying for with a professionally manufactured FG stock, and those prices won't be looking so unaffordable.

I have considered long and hard just what's involved in making any kind of a one-off stock, and also seen some relatively well done examples. I have some skills and resources for working wood, and I can do fiberglass marine repairs. I'm not a gutless wimp, but I still haven't tried my hand at stock making.

Greg </div></div>

By no means do I think I'm going to save money by making my own FG stock, on the contrary really, I know that it will be an investment of time longer than the waiting period it would take to buy one and an expense in tools and materials greater than the cost of purchasing one. Maybe by the 10th stock I'll save a penny!
laugh.gif
I want to build one for the hell of it, for what I'll learn by doing it and to be able to say "I built that". It's going to end up taking me much longer now that I live 650 miles away from where most of my tools are, at least for the time being. But, I've learned a lot in just researching the project and gained a lot of ideas on how I would like to go about building it. My hope is that I enjoy the process and end up with the stock that I have pictured in my head. Every time I handle a different stock I make note of what I like and don't like about it, what I would change about it and what features I think would work better on a different design. Some ideas I have are original, some are flat out copies, I'm going to be building for ME so it doesn't really matter. When I get into the building I intend to document it here, good or bad it will be here for all to see and learn from. That said, I imagine that with my current situation it's going to be over a year before I have any progress worth showing.
 
Re: Homemade Fiberglass Stocks?

I think we're on the same wavelength, with you being out there on point, taking the lead. As I said, I haven't yet, but that does not preclude me doing it eventually. Same reason, to see if I can make it work. It would probably make best sense for me to start with my Savage MKIIF. The factory plastic stock is way short for me, and any lessons learned could be useful for a broader audience.

Greg
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hyugo</div><div class="ubbcode-body">I just finished making a stock out of epoxy/fiberglass cloth. It took about a month to finish working on it after work and on weekends. After spending about $200 in material and all that time It would have been easier to buy a manners. </div></div> Let's see it, you can't come on here and just tell us you made an FG stock and then no details or pictures.
 
Re: Homemade Fiberglass Stocks?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan27</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hyugo</div><div class="ubbcode-body">I just finished making a stock out of epoxy/fiberglass cloth. It took about a month to finish working on it after work and on weekends. After spending about $200 in material and all that time It would have been easier to buy a manners. </div></div> Let's see it, you can't come on here and just tell us you made an FG stock and then no details or pictures. </div></div>


Here you go.
005.jpg


001.jpg
 
Re: Homemade Fiberglass Stocks?

Sorry I don't have and build pics. I've got about $200 and 20 hrs in it including paint. Overall I'm happy with the stock it's lighter and stronger then the B&C medalist it replaced and improved the accuracy by about .25moa.