DIY Stock

B

bisley

Member
Been looking at old posts regarding diy carbon fibre wrapped stocks,look like a nice project.
As I understand I make a stock out of balsa wood,or foam and cover it carbon fibre.
I'm sure I could make a balsa wood rifle stock,and balsa is quite cheap to buy.
As for carbon fibre never worked with it,and it's not cheap.
I have found material called S Glass,and it's about a quarter of the price of carbon fibre.
It appears to nearly be as strong as carbon,and more robust in some way's (less prone to shatter).

I wonder any of you have any experience with S Glass ?
Any tips and advice would be appreciated.

Thanks Adrian
 
The DIY's that I like are the normal hard-woods sliced and layered (laminated) with carbon.
Personally I would never consider a balsa type unless I needed something really light, and even then I would be hesitant simply because why use something structurally weak with something structurally strong. And like the idea of something structurally strong reinforced with something stronger yet.

My 2-cents...
Donovan
 
Lots of way to make a stock

You can do it like you suggest using a male mandrel and wrapping it with fabric and wetting it out with epoxy or make a female mould and produce a shell which can be filled with the right material for the job. As far as E vs S glass goes I don't think you will find much difference in actual use. It's like the guys that think if they bed with titanium vs alu Devcon it will shoot better or last longer, just isn't so (I use Marine Tex anyway).

So if you make a stock in wood or foam and wrap it you end up with a stock filled with a low strength material and them how do you deal with that? In some areas it will be okay but in others you will want to bond in some sort of reinforcement that connects to the shell to spread the load. If you make a female mould and fill the shell with appropriate composite materials you pretty well have what you need out of the mould and since you perfected the shape during the mould process you don't have much work to finish it.

All this depends on your intended use etc. A rimfire would work well in a covered balsa stock.

Good Luck!
 
Lam

Laminating wood and carbon/glass doesn't work that well. Have a look at one of these stocks that has been around for a few months and you will see that the wood has changed size while the composite has not. Not a good way to go, might as well stick with one material or the other.
 
Hi Ian

Ian Robertson said:
... If you make a female mould and fill the shell with appropriate composite materials you pretty well have what you need out of the mould and since you perfected the shape during the mould process you don't have much work to finish it...
Click to expand...

I would be really interested in your thoughts on what "appropriate composite materials" would be for a BR stock. Can you suggest any good reading on composites for a DIY stock maker?

Thanks
 
no problem

I have a maple, cherry with carbon fiber matte in between the layers of wood. I clear coated it 3 years ago with no problems. The carbon is a little hard on cutting bits and when you sand it the black dust gets into the pores of the wood that's hard to get out, but it make for a rigid stock. I like mine and would do an other one.
 
For those of you who aren't aware....... Ian Robertson ain't just another Irishman, he's the Robertson of Robertson Composite Stocks..... He done built him a stock or three....
 
Terry Leonard has made and sold literally hundreds of benchrest stocks made in the wood/carbon laminate method and no problems so far over these many years. My oldest Leonard is about 5-6 years old and I can see no irregularities in it or the other 3 I have. What are we Leonard stock owners missing?
 
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Books

As far as books go there are none that I am aware of. Lots of books and web info on composites but you need to pick out the bits that may apply to this app. Making stocks is very specialized. All of the methods I used except for a few I developed myself or modified a standard op. Appropriate fill materials for a BR stock would be glass bubbles, mill fibre and air. Maybe I should start a school!

Jerry, all of the stocks I have seen of laminated wood/composite have shown ridges where the comp is. If yours have not done this I guess you must have a stable climate and perhaps they were built with a climate similar to yours. There is no finish in the world that will stop wood moving.
 
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Thanks for all the advice guys,sounds like I've poked an hornets nest.
Kinda got me thinking about making a 2 part mould,thinking about dowling 2 pieces of inch and half timber together to make a stock.
Once I made the mould I Could glue the stock together,and have a go at doing a wrap.
Had quick on McMillan's You tube channel,you quick look at there moulds and cammo gel coating.
I understand stock making is a skilled art, respect the fact that people aren't going share there lively hood.
But the scary thing is some 18 old geek,could probably build one on a 3D printer.
 
Ian Robertson said:
Jerry, all of the stocks I have seen of laminated wood/composite have shown ridges where the comp is. If yours have not done this I guess you must have a stable climate and perhaps they were built with a climate similar to yours. There is no finish in the world that will stop wood moving.
Click to expand...

You'd have to take that up with Terry. You will find his stocks listed on most all the match reports I've ever read. He used several varieties of wood from Balsa, redwood, Cocabola (sp?), Walnut, White Pine (yes Pine) and a few others. The carbon fiber he uses is a woven product and I guess the weave lets it move with the wood.

I don't know how many he has out in the shooting community but he has about 400-500 underway in his shop all the time, though he only finishes and ships 2-3 each week. He has that much backorder. He ships them all over the world. There is a thread on this board somewhere from someone in Finland trying to locate him about an order. The Finnish person had made an address change since he placed the order.
 
I am glad it's working for him!

Bisley, are you at Bisley? I have been there a few times on the Canadian team. Don't try to make two halves of a stock with a mind to make two mould halves this way. Make a complete stock and them split it when you make the mould in two goes. Not hard to do when you know how, email me if you want some tips or I can post them here if anyone else is interested. vxsystemsltd@gmail.com
 
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Ask Me

Ask the questions and I will answer as briefly as I can get away with.
 
OK, I have built my "plugs" by taking a stock and filling it all in with modeling clay. Then cut it into a board (plywood) to the halfway point and laid the first half up tight to the board with appropriate 'coins' for alignment. Then flip it over and lay up the other half, remembering to drill a bunch of alignment holes before taking it apart (don't trust the coins!)

But now I'd like to make a mold for an eccentric, right-hand only stock with a rollover cheekpiece and don't know exactly how to get the first half laid up. I don't know if using a board and then modeling clay to build up to a join is appropriate....let's say it's similar to your RC12-H&H but without the add-on adjustable cheekpiece.

Or is that why you do the cheekpiece separate?

al
 
Thanks Ian

Thanks for Letting me pick your brains Ian.
Email sent.
Too cold to build stocks in my garage,will be a spring summer project.
 
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Check out R/C modeling sites.

There is quite a lot of information on composite use on R/C stuff. It's the most popular material for high performance competition aircraft.
 
Mould

Start with a stock made of any material. Fill in any openings like the action and barrel inlets etc. Bottom inlets are possible to mould in but if you leave them out the stocks will be more of a universal fit. If you need to smooth and modify the stock use a high quality body filler like used as a surfacing material. Use a block when you sand anything to maintain flats and sharp edges, sand with nothing finer than 120x. Sandpaper is a cutting tool and can really bugger things up if not used properly. Spray on a couple of good wet coats of epoxy primer or have a body shop do it for you. Sand this starting with 320x down to 600x and always use a block whenever possible. If you cut through in a few spots it's still okay. Access to the inside of the mould will be through the barrel/action channel and the butt.

Prep the plug (stock) for release using Freekote release. Apply about ten coats, a coat dries in a few seconds. If Freekote feels sticky after drying then buy fresh.

Sintra (PVC foam sheet with smooth faces) is used extensively throughout the process. 3mm, 6mm and 12mm is used to make the mould, you can glue layers of 3mm together to save buying a sheet of 6mm etc. Medium super glue and accelerator are used to glue everything together.

We are making a mould that splits down the middle and then we are making one side at a time.

Make a barrel/action opening out of 12mm of sintra shaped big enough for your fingers but smaller than any inlet you may do. This is screwed, centred, to the top of the plug under the top flange. Make a top flange using 6mm sintra, it will go 3" past the front of the plug and be about 6" wide. All this was made to create the opening to the inside of the stock and a top flange which helps to stiffen the mould. Screw 6mm sintra to the butt, this should be the same width as the top flange so when you sit it on its side on a table it will be straight and plumb. Keep all screws in the middle so sintra can be flopped to do the other side. Picture to come

The plug now sits flat on the table so fillet glue the top flange and butt flange to a sheet of 3/4 plywood in a few spots. The plywood rectangle should be about 3" larger all around than the plug. The separation/parting line in the mould must always be at the highest point. A symmetrical stock will have separation in the middle whereas a non symmetrical stock will have a separation line that may wander all over the place. Put a small square against the plug to see where the parting line should be. If you have set up properly the parting line will be in the middle on a symmetrical stock. Obviously any hollow area that will lock the part into the mould must be dealt with by adding more parts to the mould. The finished mould will split the part vertically.

Make the parting line. The parting line will run around the stock since it is oriented on it's side. Use 3mm sintra 3" wide strips. Cut blocks of 1/2-3/4 wood that are sized to put the top of the sintra right on the parting line. Super glue them in place and then super glue the sintra on top of them. It must be a tight fit to the plug, don't get glue on the plug. All this will be destroyed so don't get fancy but get a good fit. To do the curved bits carve the sintra to fit and use short bits as needed. If you need to bend sintra use a heat gun.

Keys. To align the halves of the mould make some aluminum key stock. Use ~3/32 6061 cut into strips about 1/2" wide. Set up your sander to cut about a 3 degree angle and sand the edges smooth. The draft is so the mould parts will come apart. Cut strips of this material to go all around the plug. Trim the ends to the same angle. Glue in place with a few spots of super glue, be neat and don't have squeeze out. Some vertical keys are good as well.

Plug any small gaps with Plasticine (not Play Dough!). Apply more Freekote to the plug and be sure to cover all the sintra with about three coats, avoid runs and drips on the plug. If you are really hard up to cover some gaps use plastic tape but remember it won't stick to Freekote. Only way to remove Freekote is with abrasives, it is considered a permanent release. Before anyone asks, Freekote is not good for bedding but it is the best for this type of work.

I can do this operation for most stocks in a couple of hours, you might be a bit slower! I will try to get a picture up.

Ready for layup of the first side. Next instalment.
 
Alinwa

You are certainly on the right track. Use a small square to run around the plug and where it touches will be the edge of the parting line. This will require a parting line like I have described above. Use a heatgun to bend the sintra to shape or cut it into short bits to get around the curves.
 
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