Lightweight Kimber Build with Custom Carbon Fiber Stock

[RepeatPete]

RPete - Wow - what a build!

Your technique improved by an order of magnitude on this second round. I am loving your inlet section build - using CF tube is really good in a lot of ways. It contours nicely to your rifles action and the arc of the tube adds a lot of extra strength. The multi-directional fiber orientation adds even more. Plus CF tube is relatively cheap and best of all - you don't have to fabricate it - win win.

Do you plan to leave the exterior CF surface 'raw' or seal it with something? One option that has worked really well for me is automotive clear coat applied with a Preval spray bottle. If done, make sure it has UV protection additive. Easy to apply, seals in all the stray fibers and cures rock hard.

Don't see any mention of bedding the action. Are you planning to do any? The action on my little Izhmash 7-2 .22lr is designed with bedding ridges cut into the steel of the receiver, so it's a given for my application. A bit of a apples to oranges comparison, but similar in a few ways. One main advantage I have found is bedding gives you some adjustment capability to set the barreled action dead center of the forearm slot. Doesn't really impact functionality, but it's visually nice to have the barrel dead center of the groove.

That sling looks really cool. Initially curious of the integrity of that loop over the monkey's fist closure staying put but a great ultralight + tough solution.

Designing and building from the inside (inlet box, recoil lug, sling & bipod mounts) out is the way to address such a project. Get the internals properly addressed and it's much easier to layer the outer skin around them. Dude - your weave alignment on that forearm is outstanding!

Pretty amazing how the second (and subsequent ) builds come together after some lessons learned. Biggest step is starting the first one,

Love your use of varied compression methods - haven't tried electrical tape as I thought it would leave winding lines in the cured CF, but yours looks great. Another option is window film shrink plastic from HD. Cut in long strips, wrap item and hit with blow dryer level heat to increase the compression strength. Stuff has surprising tensile strength and pulls down nicely. As you have shown, these are very doable without a vacuum setup.

You really have me thinking about a new build.

The carbon will be sealed, I have an idea for paint, but still waiting to see if it’s actually going to work. That Preval bottle looks pretty cool - I’ll have to give it a try for the clear coat after the paint.

Funny you mention bedding - I actually did that today. I used Marine-Tex gray and bedded just the chamber section of the barrel and the recoil lug as the rest of the inletting section fit very tightly already. And I don’t actually need the barrel-centering capability of the bedding, as I put in quite a bit of work previously by centering the barrel channel section of CF tube that I made, and got lucky and the barrel is dead nuts in the center.



The electrical tape does leave lines if it’s placed directly over the carbon (as my recent grip layup proved), but the peel ply and breather add enough of a cushion to spread out the compression and leave the surface even. A vacuum bag setup is definitely in the future - the pros are too hard to ignore, but I’ve been surprised how well the electrical tape works. And I’ll definitely have to try the window film - that’s genius!

Wow. Super cool.

Thank you!

 

[Gunfanatic87]

Awesome build! Definitely something to be proud of with all the work you are putting into it

 

[RepeatPete]

Awesome build! Definitely something to be proud of with all the work you are putting into it

Thanks!

I created a trigger guard by shaping a foam mold and then wrapping with CF. Then cut out the foam and bonded it onto the stock skin with a few overlapping layers of carbon. Way tougher than it needs to be, but I wanted the extra thickness for aesthetics.

 

[Skeezer69]

This is awesome!

 

[RepeatPete]

Title changed from “Custom Carbon Finer Stock around 2” to “Lightweight Kimber Build with Custom Carbon Fiber Stock” as I want to document some other details relating to the action/magazine and not just the stock build.

 

[Gobber]

That trigger guard is a great addition. I ran into the issue of needing a trigger guard that was different from the OEM and tried a few different model guards I thought I could modify. None of them worked, so I made a block with the proper inner dimension and built up the CF around it to give a usable blank. After some cutting and shaping, had just what was needed. Yours came out great and it looks as good or better than OEM. One extra advantage I’ve found is that it’s nice to have the trigger guard and ‘lower metal’ section simply built into the stock. For me it’s simpler to remove the barreled action and less screws to loose.

If you’re looking to give it a paint job, looking forward to the look you are going for. I really like the blended look of sponged splotches that let the pattern of the CF show through, but it depends on the purpose of the color coat. Automotive clear coat has always worked really well for me.

Just as an aside, working on a cocking arm handle for my little .22 plinker that is showing some potential. It really is pretty cool what can be done with pretty basic methods.

 

[RepeatPete]

That trigger guard is a great addition. I ran into the issue of needing a trigger guard that was different from the OEM and tried a few different model guards I thought I could modify. None of them worked, so I made a block with the proper inner dimension and built up the CF around it to give a usable blank. After some cutting and shaping, had just what was needed. Yours came out great and it looks as good or better than OEM. One extra advantage I’ve found is that it’s nice to have the trigger guard and ‘lower metal’ section simply built into the stock. For me it’s simpler to remove the barreled action and less screws to loose.

If you’re looking to give it a paint job, looking forward to the look you are going for. I really like the blended look of sponged splotches that let the pattern of the CF show through, but it depends on the purpose of the color coat. Automotive clear coat has always worked really well for me.

Just as an aside, working on a cocking arm handle for my little .22 plinker that is showing some potential. It really is pretty cool what can be done with pretty basic methods.

Yeah, I’m very happy with the trigger guard and it is a quick and easy affair to bolt the barreled action in, which is good because I do it a lot!

That cocking arm looks great, and highlights the amount of work for a small but complex piece. I’m constantly impressed by how useful, strong, cheap, and available in pretty much any diameter CF tube is. I also used a similar method of a CF and resin “slurry” to fill some bigger voids - just thin 3k CF shaved really thin with a sharp pair of shears into the resin and it worked great.

I did some final sanding to get the stock ready for paint.



Then a white base coat which didn’t spray great (I always seem to have problems when I try Krylon, Rustoleum always works for me) and highlighted all my surface imperfections.



Then a whole can of filler primer followed by block and hand sanding at 120 grit, then wet sanding with a 220 grit sponge pad. The surface isn’t perfect, but it’s much better.




I agree about the paint jobs that let some of the carbon show through. If I wasn’t so excited about the paint idea I’m working on, I would just leave it like this. I think the battleship grey with the “tear outs” of Carbon look really cool.

 

[Stearinlys]

"RepeatPete Pattern"

Love it! Looking great so far!

 

[Harvey_NW]

Man, that thing looks badass and you've done a fantastic job!