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10-17-2019, 05:05 AM | #1 |
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Join Date: Nov 2016
Location: Bilbao (Spain)
Posts: 445
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DIY: How to cast PU handles for guns
Hello all,
About time to contribute with something (hopefuly) useful for the community. Not rocket science AT ALL and it is just my way of doing it. I made my first gun slaping plywood slabs (epoxy) over a stainless rib welded to a plate that integrated the trigger guard and loading pad (ala Abellan guns but with fixed handle). Boatload of work and very heavy. For my second gun I used a cast PU handle that a friend of mine (who makes guns for sale) gave me. He makes them in batches using molds and gave me a few hints. I thought I could illustrate the process for anyone who wants to do the same. The biggest benefit is that you will get the exact same handle everytime. First I put together a clay model Kids are always willing to help (allow me to introduce my now 5yo daugther) Starts to look like something And after some tweaking, allowing to dry, shrinking, wetting, drying again, sanding, etc... I came up with this. As per clay manufacturer instructions, for my purpose, I didn't need to cook it, just let it dry enough. I gave it a couple coats of clear coat to get a smooth finish After drying and taking it home, I used some epoxy putty to fix a few dents so they didn't print on the final cast and rigged a few wires (TIG wire, mind you) to separate it from the bottom of the container. Yes, that's my kitchen countertop. Two things are going on in this picture. I am mixing the silicone for molds up front and in the back you can see a small bottle with industrial vaseline and a brush. the vaseline is used as a release agent for the silicone not to adhere to the model. Before mixing the silicone I took some measurements to know the volume of my model and find a suitable container to make the mold. I got lucky and realised that I could very well mix all the silicone I had bought and just place the model inside. The silicone container would make the perfect mold. Actually the propper procedure to mix anything that needs to chemically react is to pour the two products into one container, mix, mix some more, then pour into another clean container, mix some more and then use. This prevents some material (usually at the bottom edge or walls of the container) from not getting properly mixed. I didnt do it and this is exactly what happened to me in a couple spots (does not affect the mold) that didn't cure properly. Now, a few things happened before taking this picture. First I cut in half the plastic container to the best of my ability with a utility knife. Then I cut through the silicone all the way to the model as little as possible to reduce future misalignment of the two parts when casting final parts. Then mocked it up for the picture A few pictures of the mold As you can see, I got a few bubbles in the mold. Anyone arround here owns a vacum chamber I could borrow?? Measuring the volume of the handle to see how much PU resin it required 200ml aprox. And now the fun part. In my second gun I used a Meandros LS mech wich is somewhat heavy and it is one of my favourite mechs (screw on installation from the top) so chances are it is the one I will be using in the future). To compensate somehow this heavy mech, I decided to use a PU resin that floats. It is called Smoth On Featherlite. Usually sold for those who craft their own fishing lures. I hope it is strong enough (will be reinforced with some CF cloth wrap. CocaCola can used for mixing the two components (volume marked on the inside). Mixed, poured and waiting for it to cure. Silicone mold is kept in the container it was created to help with the alingment (even though is very hard and does not deform easily) And... TADA!!! Now it is just a matter of sanding the top off (accoding to how high you want the handle), glueing and screwing from the top, through the wood and into the PU itself (predrilling recommended to avoid splitting it) I have one attached to a WIP gun, I can also show how I attach it if someone is interested. Mikel |
10-17-2019, 08:29 AM | #2 |
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Join Date: Mar 2006
Posts: 4,245
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Re: DIY: How to cast PU handles for guns
Very good, plus no problems about it fitting your hand. As you split the mold to get the item out you could cross hatch the mold surface to produce ribs or a checker pattern on the grip.
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10-17-2019, 09:08 AM | #3 | |
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Join Date: Nov 2016
Location: Bilbao (Spain)
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Re: DIY: How to cast PU handles for guns
Quote:
However the way I attach, color and coat the handle it really wouldn't have helped much. After shaping and attaching it to the wood (epoxy + screws) I usually reinforce the joing with some strips of CF so the texture would have been buried under the cloth and the resin. I try to make my handles stand out so I color them in yellow or orange. I coat them with top coat epoxy resin with some tint. Two coats. And when the second coat has already cured to a gel consistency, I sprinkle salt on it. Once cured, I rinse it under the tap and all the salt disolves, leaving a bunch of tiny craters in the epoxy. Very veeeeeeeeeeeeeery grippy! Mikel |
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10-17-2019, 10:40 AM | #4 |
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Join Date: Sep 2012
Location: Rocky Point, NY
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Re: DIY: How to cast PU handles for guns
This is great. Thanks Mikel. I will be trying this at some point!
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10-17-2019, 12:07 PM | #5 |
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Join Date: Apr 2005
Location: Port Charlotte Fl
Age: 76
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Re: DIY: How to cast PU handles for guns
All that's missing is a picture of the finished product(s).
Sounds like you have done several. |
10-18-2019, 02:25 AM | #6 | |
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Join Date: Nov 2016
Location: Bilbao (Spain)
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Re: DIY: How to cast PU handles for guns
Quote:
So far I have put together two full guns and another two are WIP. Yesterday I posted a monster thread (arround 150 pics) of the build of my second one and this incorporates a glued/screwed PU handle. Let me extract a few pictures here: Adjusting handle to stock Gluing with epoxy Screws (predrilled and smeared with epoxy) Reinforcing with CF Cloth (the divots you see are meant to insert the rearmost end of the trigger guard) https://i.ibb.co/kM9fFps/107-Handle-Area01.jpg Coloring and coating the handle with epoxy top coat. Last coat gets sprinkled with salt to provide texture once rinsed under the tap (once fully cured) And the final product In hand I guess now DEANMC understands what I asked him in his last roller build about the reinforcement of the handle/stock joint with CF (even though his is integral in wood) Mikel |
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10-18-2019, 02:45 AM | #7 |
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Join Date: Mar 2015
Posts: 482
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Re: DIY: How to cast PU handles for guns
great lesson ,reliability of PU vs wood is their any big difference ?
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10-18-2019, 03:09 AM | #8 | |
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Join Date: Nov 2016
Location: Bilbao (Spain)
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Re: DIY: How to cast PU handles for guns
Quote:
I have also seen (at least in Spain) several brands selling PU handles just like this for those who want to make their own gun. They are sold anywhere between 20-30€. The great benefit for people who are pumping guns (for profit) is that you forget about the shaping part, which is time consuming. If you buy the PU resin in bulk, it is also cheap. A maker who does custom jobs could even have several molds (sizes) and ask the customer for glove size to fin the one that suits him better. Or if the customer comes to the shop, let him grab all the models and choose the one that suits better. Also, not having grain, it doesn't want to split. Being synthetic does not absorb water, etc. I am pretty sure there are many different PU resins out there and some will certainly be perfect for this purpose. If you are worried about it breaking, you could always cast them arround an inner metal rib. I though about it but it goes against my current light-is-right moto. We don't need huge cannons here in the north of Spain for our type of fishing so we don't have much wood to compensate heavy items. Mikel |
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10-14-2020, 09:40 PM | #9 |
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Join Date: Mar 2015
Posts: 482
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Re: DIY: How to cast PU handles for guns
Did u try the handle ?3 rubbers heavy gun recoil could break it or not?idea is great but the cross section should be accurate to distribute force equally and prevent gun from shifting as a reaction to recoil ,I checked the mechanical properties it is near to epoxy resin only difference in buoyancy so for big gun may be u can use epoxy to add ballast to ur gun .
Last edited by doyenofcastle; 10-15-2020 at 01:20 AM. |
10-15-2020, 04:19 AM | #10 | |
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Join Date: Mar 2015
Posts: 482
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Re: DIY: How to cast PU handles for guns
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10-15-2020, 04:38 AM | #11 | |
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Join Date: Nov 2016
Location: Bilbao (Spain)
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Re: DIY: How to cast PU handles for guns
Quote:
I am not pumping out guns as fast as I would like but so far my main problems are related with lack of buoyancy... So I haven't added any lead or weights of any kind to my guns. Will have a look at it but I am currently using this product: Feropur-pr55-e55-resina-poliuretano-rigida. Once cured is a tad negative buoyant but just to make sure I add a couple spoons of glass microspheres... which helps with the sanding and insures it is neutral or buoyant. And it is cheeeeeeeeeeeeeeeeeeeeeeap The one you just mentioned is more than double the price (I don't doubt it is a great product, but anything that comes from Smooth On is going to be pricy). Mikel |
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10-17-2020, 09:01 AM | #12 | |
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Join Date: Mar 2015
Posts: 482
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Re: DIY: How to cast PU handles for guns
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06-09-2023, 07:03 PM | #13 |
the deeper the blue.....
Join Date: Oct 2016
Posts: 498
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Re: DIY: How to cast PU handles for guns
anyone done up moulded recoil handle with materials available Australia?
love me shaped wood handles but lotta work, and every one a little bit different, be nice to do some popouts, give the OCD a rest |
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