Ian Roberston (robertson composites) used to take part in the discussions here and I always enjoyed reading his posts when it came to making composite stocks and such. He is a fine craftsman and I know many folks miss his presence making rifle stocks for canadians. Thing have come a long way in the stock making arena.
Composites
- Thread starter diopter
- Start date
for advice.... I would say check out Composites One if you have not already. Literally months of learning to do on existing processes and continued updates on cutting edge materials and processes. The hobbiest or light manufacturer has some totally out of the box options these days..... just gotta wrap your head around some of this stuff first.
another cool site i get some of my materials from is sculpture supply canada .... very cool site
Tape your breather cloth in place at the other end, then it wont pull off. Your part looks good, maybe not so much vacuum...just try a little less, maybe a half a bar...Air bubbles in the corners can be full with epoxy after , but a little less vacuum, may help with the bubble.
Yes you can change the cure time by mixing a slower hardener with the fast, just keep the ratio the same.
Keep up the great work!! looks like your almost there!
Yes you can change the cure time by mixing a slower hardener with the fast, just keep the ratio the same.
Keep up the great work!! looks like your almost there!
Starting to feel like a poor preschooler from the slums at a university lecture.But please don't dumb it down. Great info.
I do have some more questions.
Q1) I find the Carbon fiber cut to size sheet expand once the resin is applied. Normal?
Q2) My corners did not come out as nice as I wanted. Any Suggestions on how to patch them after sanding to get sharp air tight corners?
Q3) I heated my first batch of resin to help it flow. It seems to have gelled much faster than I expected causing the ripples on the top surface.
Should I use a the 50/50 mix of the fast and slow cure rate hardners or just go for the slow one?
Seems Breather layer was pulled by vacuum to the side where the hose was.
The Teflon release is so slick the resin beads on it. Looks like I'll be force to apply resin to the CF before it gets to the mold.
Release was easy once I trimmed it as close to the mold edge as I dared using a Dremel cutting disc and sander. Used tooth picks as wedges between piece and mold.
After trimming with Dremel cutting disc/sanding and release. Inside.
Outside
Inside corner.
speaking of projects in composites..... I'm building a custom ice racing/ice fishin machine out of a crafstman 18HP 5 speed lawn tractor LOL
This winter I'll be fabbing up all the body components and a custom insert for my ice fishin sled to compartmentalize it for gear and such. I'll make sure I have a camera handy as I'll be using a few different processes and materials that might interest folks. Iif It's cool with the OP, I'll throw the project in here when i have time.
This winter I'll be fabbing up all the body components and a custom insert for my ice fishin sled to compartmentalize it for gear and such. I'll make sure I have a camera handy as I'll be using a few different processes and materials that might interest folks. Iif It's cool with the OP, I'll throw the project in here when i have time.
Please do.
I'm patching up the corners, looking for stock CF sheet minimum 26 x 15 inches for front cover, a thin way to stiffen my "Frankenstein" back-shell, and a way to make a lip around edges for vacuum seal. Emailed Canada composites already to see if they can help for the stock items.
I'm patching up the corners, looking for stock CF sheet minimum 26 x 15 inches for front cover, a thin way to stiffen my "Frankenstein" back-shell, and a way to make a lip around edges for vacuum seal. Emailed Canada composites already to see if they can help for the stock items.
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45ACPKING.
I know you're protecting your work so if I am being too nosey let me know. But I assume you're building a silicone mold with a fiberglass mother mold on the outside of that?
If so how is the silicone for repeatable dimensions? Does it not deform a lot once it's under vacuum?
Myself and a buddy have a couple rifle stock molds that we have built and are planning on building a few more, and I have been looking at attempting a silicone based mold but most of the info I can find on it is for casting things like masks and such.
So I have been reluctant to try it. But I do know I don't like our current epoxy mold material, It's not the nicest to work with.
I know you're protecting your work so if I am being too nosey let me know. But I assume you're building a silicone mold with a fiberglass mother mold on the outside of that?
If so how is the silicone for repeatable dimensions? Does it not deform a lot once it's under vacuum?
Myself and a buddy have a couple rifle stock molds that we have built and are planning on building a few more, and I have been looking at attempting a silicone based mold but most of the info I can find on it is for casting things like masks and such.
So I have been reluctant to try it. But I do know I don't like our current epoxy mold material, It's not the nicest to work with.
As far as vacuuming down a silicone mold goes...it can be done. As in your case, you,..or I would start with a urethane base, as in a cast urethane foam rifle stock (made from a fiberglass mold). Then wrapped in carbon fiber,or glass and then carbon, depending on how flexible, and the weight you are looking to achieve. All material is put in DRY...no resin at this time...maybe a little spray, to help hold everything together. Then the silicone mold is placed around the core material, that you have wrapped, with glass, carbon..etc And then the fiberglass outer shell, that holds the final shape.
The only real purpose of the silicone is to allow for under cuts, holes,bad angle...etc. in the mold, that would not be allowable in a standard type fiberglass mold.
After the mold is fully assemble,.....urethane core...wrapped in fiber...glass or carbon....inner silicone mold...wrapped in the fiberglass outer shell. This would be the time ,that the vacuum would be applied ...drawing in on the assembled parts, at this time is where the resin is introduced in to the closed,low pressure, foam core mold. It know as RTM light, and it work very well.
So the vacuums is on, parts been drawing down...( the vacuum is not just introduced , in just one spot, but along the edges of the mold, flange area) . The resin can be introduced at one end or in a couple of spot, sometimes a little trial is required.
Usually the vacuum is applied along the flange area, in multiple location, with lengths of clear hoses...maybe 1/4 inch ID,as the resin become visible, in the clears vacuum tubes...one at a time...with the one closest to the resin supply showing first, you pinch them off , with vicegrips, or clamps of some sort, until the last and furthest away tube has resin showing in it.
Because the part, was under vacuum all the time, the finished part, should have the lowest, resin to fiber ratio, that could be achieved. If at anytime , while you are introducing resin into the mold, you loss vacuum, you run the risk of "ballooning" the part...part become resin rich...losing strength and making it brittle, so maintaining, vacuum is very important ...put a valve on your resin output line and control the amount of resin, and the speed it is delivered at.
The resin supply is just gravity supplied...not pressure pots, something simple ...a container with a hose held to the bottom of it, with a , on/off valve to control resin speed and maintain vacuum.
The idea is, you can build the tights parts available,... with the same amount of material every time.
Built in "grip" areas can be made into the silicone molded surface, along, with under cuts...with removable piece, that can be taken in and out of the molds, for thing like bottom rails, larger pawn swell...left..right stocks...etc out of the same mold.
I might have got off topic here, just started rambling....lol
It would take a whole pile of typing and uploading of videos for anyone to be able to decipher how I make composite parts... including rifle stocks.
My molds are multi part molds using a structural/tool grade silicon product. I worked closely with the folks at Smooth On to develop the final mix rate and addatives.
My molds are actually made of aluminum, copper, casting concrete and silicone.... with a few stainless steel fittings, barbs and nuts and bolts.
I would venture to guess that no stock maker out there is doing what I am doing but I do know of at least one other who is doing something similar in process.
I use very little dry material these days. I got tired of the fibres and dust and need for huge vacuum system attached to every work space. I got tired of the fumes produced in traditional open and vacuum bagged systems. I got so tired of needing a respirator for 8 to 12 hrs a day....... I quit making rifle stocks for over a year.
Now there's a small booth for any sanding or drilling and a smaller booth for any dry cutting of materials. Everything else is kept as dust free as possible with down draft natural gas heating in the shop.
I use Pre preg materials that are Thermoset..... so they require a heat up and cool down process to achieve proper cure and also to bring the other properties of the resin to full strength. Pre preg is just a fancy word for pre impregnated material or material with the specific resin ratio already wetted out into it and a heat activated hardener is already in it. The ration is the perfect amount of resin for that weight of material. Sometimes I have to make it myself but that is another thread. I get my orders thru Composites One on 100ft rolls , both standard width and also in rolls of strip in 4" and 2" wide.
I cut all my patterns and lay those into my molds, laying in mold parts as they fit in and bolting where applicable. So when both sides of one of my rifle stock molds is complete and all the components laid in , the two halves are the closed and bolted up. A 1/2 inch thick custom made silicon bladder with a inbedded 1" aluminum flat bar lip on both top and bottom, is fastened and bolted up with the mold inside it. I need to skip part of the description here and I apologize but it's the secret part hahaha.
The bladder has a vaccum line and also sealed lines that pass thru it to the inside of the mold. Same at other end with a line passing outside the bladder.
The Bladder is brought to negative 2 atmospheres and held for duration of process. The secret system that begins the mold temperature ramp up is turned on , as it the resin pot attached at one end. Once the ramp up temperature hit's my resin's flow rate, the secondary vacuum is activated and also brought to negative 2 atmosphere and the resin pot begins to empty into the mold. Once a predetermined amount of resin has collected in the overflow on the vacuum end of the mold, the resin line is clamped and the 2 vacuums are left on for the rest of the curing time. Temperature has been slowly increasing to peak cure temp and then system begins the ramp down phase , slowly bringing the temperature down to room temperature. The parts come out ready to use save for cosmetics like a wet sand and polish. Sometimes there is minor flashing to remove here n there but minimal and easy done with a small razor knife in most cases.
If you google Composites One Processes , read up on Light Resin Transfer Method , it's basically just the evolution of vacuum bagging but is the stepping stone to developing a process specific to your needs. I have no need for breather mat , mold release agents and all the fumes are trapped in that bladder and are rendered inert by the time the cure is complete. It's a beautiful thing
What turned me on to silicon rubbers for mold making actually came from spending some time hanging out with a guy who works in the special effects industry.
Anyways..... I'm a member of the Closed Mold Alliance and turning people on to composites and seeing what they come up with is pretty fun. Also it's guys like all of us that drive the industry forward by brainstorming up new ways to encorporate composites and dreaming up new processes..... it's just fun stuff
My molds are multi part molds using a structural/tool grade silicon product. I worked closely with the folks at Smooth On to develop the final mix rate and addatives.
My molds are actually made of aluminum, copper, casting concrete and silicone.... with a few stainless steel fittings, barbs and nuts and bolts.
I would venture to guess that no stock maker out there is doing what I am doing but I do know of at least one other who is doing something similar in process.
I use very little dry material these days. I got tired of the fibres and dust and need for huge vacuum system attached to every work space. I got tired of the fumes produced in traditional open and vacuum bagged systems. I got so tired of needing a respirator for 8 to 12 hrs a day....... I quit making rifle stocks for over a year.
Now there's a small booth for any sanding or drilling and a smaller booth for any dry cutting of materials. Everything else is kept as dust free as possible with down draft natural gas heating in the shop.
I use Pre preg materials that are Thermoset..... so they require a heat up and cool down process to achieve proper cure and also to bring the other properties of the resin to full strength. Pre preg is just a fancy word for pre impregnated material or material with the specific resin ratio already wetted out into it and a heat activated hardener is already in it. The ration is the perfect amount of resin for that weight of material. Sometimes I have to make it myself but that is another thread. I get my orders thru Composites One on 100ft rolls , both standard width and also in rolls of strip in 4" and 2" wide.
I cut all my patterns and lay those into my molds, laying in mold parts as they fit in and bolting where applicable. So when both sides of one of my rifle stock molds is complete and all the components laid in , the two halves are the closed and bolted up. A 1/2 inch thick custom made silicon bladder with a inbedded 1" aluminum flat bar lip on both top and bottom, is fastened and bolted up with the mold inside it. I need to skip part of the description here and I apologize but it's the secret part hahaha.
The bladder has a vaccum line and also sealed lines that pass thru it to the inside of the mold. Same at other end with a line passing outside the bladder.
The Bladder is brought to negative 2 atmospheres and held for duration of process. The secret system that begins the mold temperature ramp up is turned on , as it the resin pot attached at one end. Once the ramp up temperature hit's my resin's flow rate, the secondary vacuum is activated and also brought to negative 2 atmosphere and the resin pot begins to empty into the mold. Once a predetermined amount of resin has collected in the overflow on the vacuum end of the mold, the resin line is clamped and the 2 vacuums are left on for the rest of the curing time. Temperature has been slowly increasing to peak cure temp and then system begins the ramp down phase , slowly bringing the temperature down to room temperature. The parts come out ready to use save for cosmetics like a wet sand and polish. Sometimes there is minor flashing to remove here n there but minimal and easy done with a small razor knife in most cases.
If you google Composites One Processes , read up on Light Resin Transfer Method , it's basically just the evolution of vacuum bagging but is the stepping stone to developing a process specific to your needs. I have no need for breather mat , mold release agents and all the fumes are trapped in that bladder and are rendered inert by the time the cure is complete. It's a beautiful thing
What turned me on to silicon rubbers for mold making actually came from spending some time hanging out with a guy who works in the special effects industry.
Anyways..... I'm a member of the Closed Mold Alliance and turning people on to composites and seeing what they come up with is pretty fun. Also it's guys like all of us that drive the industry forward by brainstorming up new ways to encorporate composites and dreaming up new processes..... it's just fun stuff
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Great posts gents. Makes me feel like I'm making flint tipped spears in an age of motorized Gatlings and lasers.
I'm having a hard time getting a nice finish on the Breather side of the piece. Resin make craters as it drys. Degreaser? Tried multiple coats and sanding in between.
Made a flat panel for the open side and still cutting/trimming it down to fit inside. Still need to figure out how to make a lip for flat panel to seal against.
Three layers of 7.3oz Carbon fiber, came out to be 1mm± thick.
I'm having a hard time getting a nice finish on the Breather side of the piece. Resin make craters as it drys. Degreaser? Tried multiple coats and sanding in between.
Made a flat panel for the open side and still cutting/trimming it down to fit inside. Still need to figure out how to make a lip for flat panel to seal against.
Three layers of 7.3oz Carbon fiber, came out to be 1mm± thick.
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Basically idea is for a light, large surface area vacuum gripper to mount on a robot arm for photo-resist laminated copper plates to feed and remove them from a rail mounted vacuum plate that hold it during imaging with a UV laser. Large surface needed to have accurate indexing of plates.
This comes close except for size and shape.
This one is close in vacuum gripper size to what's needed but way too heavy for weight load, and expensive.
This comes close except for size and shape.
This one is close in vacuum gripper size to what's needed but way too heavy for weight load, and expensive.
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far out
i wouldn't have guessed that in a million years haha. Gotta say, that's a cool project.
Moldable silicone products might be of real use to you in this project in conjunction with what you already have there......
bit of a side track but I have an old 3horse merc outboard that i really like. It's perfect speed for fishin and real quiet. Anyhow, leg seal went down by the prop and no where on earth could i find one or anything similar i could use. The original was still there so I carefully preserved it and found a piece of solid copper wire that was just slightly larger diameter and bent it into a perfect ring, soldering and smoothing the joint. Then I made a 2 part plaster cast and made an exact copy of the ring with the smooth on silicon rubber product. Fit perfect and she leaks no more
i wouldn't have guessed that in a million years haha. Gotta say, that's a cool project.
Moldable silicone products might be of real use to you in this project in conjunction with what you already have there......
bit of a side track but I have an old 3horse merc outboard that i really like. It's perfect speed for fishin and real quiet. Anyhow, leg seal went down by the prop and no where on earth could i find one or anything similar i could use. The original was still there so I carefully preserved it and found a piece of solid copper wire that was just slightly larger diameter and bent it into a perfect ring, soldering and smoothing the joint. Then I made a 2 part plaster cast and made an exact copy of the ring with the smooth on silicon rubber product. Fit perfect and she leaks no more
It's funny, I was looking thru old photographs today finding stuff i want to scan into digital format and I stumbled across pics that had the beginnings of the first rifle stock i designed and built from scratch. I didn't have internet back then and lived in an old farm house out in rosedale bc, oh back around 2000. Anyhow, no books, no internet but I'd already worked with composites and being a crafty kinda guy I got too it. Plan was a fiberglass lightweight stock for an old model 64b 22semi.
I drew the stock up and then made a full replica in balsa wood, building that stock layer by layer, glueing sanding shaping fitting..... took me quite a few weeks but in the end I had a complete, pistol grip stock that fit the rifle like a glove.
I used a clear spray to seal the stock inside and out and then cast an inside mold of the action inlet and barrel channel.
I made it so i could seperate the stock perfectly in half , freeing the action/barrel channel mold and then made a plaster cast mold of each 1/2 of the outer sides. I used hot wax to shape dams to keep the plaster out of the barrel channel and action inlet.
I ended up with 2 molds and a plug of the action inlet and barrel channel.
The whole process was just dreamed up in my head , mashing together different things i had worked on in the past. It was kinda poorly thought out and caused the man hours to literally go on forever haha
But , it did work...... I waxed out the mold sets and then layed in gelcoat , once that was ready I hand layed in pigmented layers of fiberglass and the plug section I carefully cut pieces and built up the fiberglass on the plug to form the action inlet and barrel channel. I used a dust buster vacuum for the bagging process LOL
Plan was to marry the 3 components , each constructed to an average thickness of 1/8" and then use expanding marine foam to fill the core and any empty void in the construction.
Again.... it was all kinda poorly conceived and I worked on it off n on for what seemed like months. In the end though I did finish that stock and I even modified it to have an windage and elevation adjustable lazer in the forstock LOL In my beginng days of CGN I actually sold that rifle and stock to a fella from here.... dukeoflawnchair I think it was......
I learned a crap load from that project and have been working with composites off n on ever since. Looking back, that whole project was awefully primitive ..... but it worked haha
I drew the stock up and then made a full replica in balsa wood, building that stock layer by layer, glueing sanding shaping fitting..... took me quite a few weeks but in the end I had a complete, pistol grip stock that fit the rifle like a glove.
I used a clear spray to seal the stock inside and out and then cast an inside mold of the action inlet and barrel channel.
I made it so i could seperate the stock perfectly in half , freeing the action/barrel channel mold and then made a plaster cast mold of each 1/2 of the outer sides. I used hot wax to shape dams to keep the plaster out of the barrel channel and action inlet.
I ended up with 2 molds and a plug of the action inlet and barrel channel.
The whole process was just dreamed up in my head , mashing together different things i had worked on in the past. It was kinda poorly thought out and caused the man hours to literally go on forever haha
But , it did work...... I waxed out the mold sets and then layed in gelcoat , once that was ready I hand layed in pigmented layers of fiberglass and the plug section I carefully cut pieces and built up the fiberglass on the plug to form the action inlet and barrel channel. I used a dust buster vacuum for the bagging process LOL
Plan was to marry the 3 components , each constructed to an average thickness of 1/8" and then use expanding marine foam to fill the core and any empty void in the construction.
Again.... it was all kinda poorly conceived and I worked on it off n on for what seemed like months. In the end though I did finish that stock and I even modified it to have an windage and elevation adjustable lazer in the forstock LOL In my beginng days of CGN I actually sold that rifle and stock to a fella from here.... dukeoflawnchair I think it was......
I learned a crap load from that project and have been working with composites off n on ever since. Looking back, that whole project was awefully primitive ..... but it worked haha
