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Devcon 10110 use
Those of you that have used Devcon 10110 in bedding projects; How do you measure the portions of resin and polymer? by weight or volume? and how critical is the ratio? I plan to do more research, but if you have any tips, I would like to hear them!
-Eric -
9 Replies
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Stole this from “Sniper Forum”…
Re: Proper Devcon Mixing
Easiest and safest:1) Put mixing container/plate on reloading scale, and tare with the container.
2) Use a mixing utensil (NOT an effing popsice stick…you need a degreased and dry flat-blade screwdriver to mix this stuff well and to use the blade as a scraper to mix all the way to the bottom of the pile of putty) to put in you estimated amount of 10110 Steel and get all you can OFF the blade of the screwdriver. Go heavy, if you doubt the amount you have…trust me, it's lots easier to throw a way a little hardened epoxy than to un-bed a rifle later to mix more epoxy because you didn't get good fill and squeeze out).
3) Weigh again…write this number of grams or grains down, and then divide the number by 9 to determine exactly how much hardener you need.
4) With the steel and container on the scale, tare the unit again.
5) Using a smaller utensil (and a popsicle stick might work for this), scoop out some hardener from the short can. Put it on the scale. Use popsicle stick to slowly transfer some hardener onto little “piles” on top of your puddle of steel until you reach the 1/9th ratio you need for proper cure and strength.
6) Once I have both in the container, and ratio correct, I clean up everything, put the CORRECT lid back on both cans, put the cans back in the box, and check the CLOCK…once I mix, I have about an hour at 70-degrees before the epoxy starts to get tougher to work with and clean up.
7) Get the CLEANED OFF screwdriver from earlier back out, and mix the crap out of this stuff until your hand starts hurting. Scrape the bottom and/or sides of the container multiple times into the middle, and make sure to use another screwdriver blade (also cleaned and degreased) to carefully clean off the bigger blade and remix the crap off of it. By the end of 3-4 minutes of stirring and scraping, there should not be ANY white hardener visible anywhere in the mixture, on either tool, nor anywhere through the strata of the pile or the mass left on the screwdrivers.
8) Clean off the smaller screwdriver.
9) Use larger screwdriver to start applying epoxy to the stock and/or action and/or pillar and/or bottom metal…
Get moving, you've only got about an hour. I'm to the point where I can mix, apply, compress in to stock, and have a rifle upside down and completely cleaned up to cure in about half an hour…but I've done a few.
The trick to good glass or glass/pillar bedding jobs is in the hours spent on preparation of the stock and action PRIOR to even opening the Devcon Box.
Tape or wax EVERYTHING you don't want epoxy to stick to permanently. You WILL have this gray crap on your hands or gloves, and in handling the rifle, you'll get little spots of it everywhere on the metal and stock. If you didn't tape or wax, cleanup later can be expensive and costly.
Key here: BEFORE the epoxy is cured, but AFTER AFTER AFTER you have compressed the barreled action into the stock as far as it can go..remove all the edging and stock covering tape that has epoxy on it..if that shtuff hardens on your tape at a seam, you are royally screwed in trying to get either one off later.
Clean up EVERY last bit of epoxy from where you don't want it later BEFORE you go to bed for the night. Q-tips and toothpicks and razor blades are useful for beveling and removal.
Last: after you stop fretting and searching for epoxy all over the rifle and you turn the whole thing upside down to cure, don't freakin' touch it for 6 hours. Don't. Go to BED. Get up in the morning, go in, and CAREFULLY get the bit and handle out and JUST CRACK the bolts loose about a 1/4 turn, then return to battery; if you used only tubing as for initial install of floating pillars, just leave it alone. Now, when you get home from work, the epoxy will be hard enough to pop the action loose without flexing, denting, or breaking under the tension.
Take all your fasteners out if applicable, take the bands or tube off, then gently pull down on the stock at the action, and up on the barrel, holding as close to the forend tip as possible.
If she doesn't come loose with moderate effort, don't freak out, and do NOT start hammering. Step away from the rifle…come back in half an hour and after you have spoken with one of us about it…it will come loose, but if you got a good tight bed, it will not be easy to get loose the first time out.
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just what i needed, thanks Dog Down!!
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Out of all the rifles I've bedded with 10110, I doubt I've ever had the same mix ratio. I measure with a couple tablespoons, and eyeball it. But then, I've mixed alot of Bondo in my day. They've all turned out perfect.
I guess the weighing it on a scale is a good idea… ::)
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I tried weighing it on a scale, but it was too heavy and maxed my scale out, so I also did it by eye and never had a problem.
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Out of all the rifles I've bedded with 10110, I doubt I've ever had the same mix ratio. I measure with a couple tablespoons, and eyeball it. But then, I've mixed alot of Bondo in my day. They've all turned out perfect.
I guess the weighing it on a scale is a good idea… ::)
Well…it depends on how much you believe in “measurable results”. ;D
I have used epoxies for 20+ years – in industrial application/critical situations ( fixing bridges, dams and elevated parking decks and even some “hot side” nuclear power plant work) in which batch retains were kept and tested for the resultant strengths. Really measured strength…not “well it seemed to get hard enough for me”…. ( that's what she said… ;D) Inadequate mixing – or “Off-ratio” mixed materials can create “creep”. Creep occurs when you have dynamic loads that in this case – are much like the physics that result at the action/stock/recoil lug interfaces when you you squeeze the trigger, and a round causes recoil. “Creep” is materials that seem to have hardened – but managed to get pushed, or squeezed out from their original placement once cured at the time of installation. It is something that would me measured in thousandths – but in some applications for epoxies ( as mentioned above in my old line of work) shows that we get less than the best performance when we have “creep”. Creep allows some movement in the structures where we were trying to stop said movement.
And – if the mix ratios were off by more than 3% – the test results would show that the compressive, tensile elongation, and tensile numbers were not up to the manufacturer's specs. A good predictor of creep…Since you cannot remove what has been mixed and injected under thousands of pounds of pressure – you MUST get it right in that situation.
So – I am not comparing bedding a rifle to my old vocation – in fact, this will be my first attempt to bed a rifle. But, you can bet your butt-pad that I will mix it correctly. By weight if that is what the manufacturer says. By volume if that is o.k. with them – but thoroughly none the less.If you have a friend that is a dentist – ask him for some of the tools that he will discard – after sterilizes and inspects them. The picks are great for bubble puncture, and they actually use some small spatula like tools sometimes for mixing dental grade acrylic adhesives.
Just have plenty of tools on hand, and use what feels best for you to remove-mixed materials from the main mixing tool,and get it re-incorporated into h batch of material. That will help you stay “on target” with your mix ratio accuracy.You can get a decent digital scale from any store nowadays. They are cheap and popular due to our need for dieting. Less than $20 bucks – and often, $10.
I like clear mixing cups, so I can tell where there is any virgin material remaining. As well, I get some cheap,small, stiff rubber blade spatulas from the kitchen store. And – I get tongue depressors – and cut one end of them off – so that is is “square” to the bottom of the mixing cup. This allows you to get into the corners of the cup.
Folding material in toward the center from the outer edges – without entraining air is key with many of they heavy viscosity epoxies.Hope this helps….I will have questions about exactly WHERE to bed the stuff in my stock. I may know how to mix it – but, this specific placement of epoxy is a first for me.
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Interesting stuff – thanks.
Watch some of Nathan Foster's vids on YouTube. He runs a business in NZ called Terminal Ballistics Research and he really knows what he's doing. Follow his advice and you can't go wrong.
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Been watching some of those J. Liked them so much, I ordered some of his books.
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Good on you. I have them all too and I'm a better shot, better informed and better at getting the most from my rifles. He knows what he's talking about alright.
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I find that he uses a very pragmatic…and not dogmatic approach to all subjects ;).
That he is a long range hunter, AND a gunsmith….makes for a realistic, and practical look at every subject he writes about.
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