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Old November 25, 2020, 10:49 AM   #1
kilotanker22
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Glass Bedding a Polymer Stock

I intend to bed a factory Remington 700 ADL stock. I know that some epoxy resins have trouble sticking to some polymers. My intention is to use 60 grit sand paper to rough up the entire interior surface of the stock. Then I intend to drill some very small lateral holes in the polymer to aid in the glass squeezing into them and providing multiple mechanical bonds. Of course the stock will be degreased and cleaned prior.

I also intend to bed the entire barrel channel with the bedding compound and then relieving it with a wooden dowel and sand paper to float the barrel channel except for the first part of the barrel before the taper.

My question is, what bedding compound should I use for bedding to a polymer stock? I am reasonably certain that with the provided mechanical bonds and bedding the interior of the stock in its entirety should provide sufficient grip for the compound to adhere to the synthetic stock.

Am I missing some important piece of information? Or should this method work just fine?
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Old November 25, 2020, 05:40 PM   #2
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I have no idea what the plastic you have is. No bedding or adhesive commonly available will adhere well to some of the thermoplastics. I have a Browning thermoplastic stock that has a touch of factory bedding that appears to be Devcon Flexane 80 two-part polyurethane rubber. That may adhere for you, though you will probably need a primer. There is also the trick of heating the plastic with a hot air gun to create a better surface to bond to. Other schemes include drilling holes to put dowels in or driving small screws partway into the plastic to give the bedding to hang onto on the assumption it's never really going to stick reliably to the plastic.

I would call the maker and see if they know of something that will stick to it.
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Old November 25, 2020, 08:40 PM   #3
dakota.potts
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I've always used Marine Tex and had fantastic results. Never tried a factory Remington stock but I've done plenty of other polymer and fiberglass stocks from Magpul to Macmillan and Marine Tex bonds hard to it. I have never really had to alter a stock to get it to stick but you can do so if you think it will help. Many polymer stocks have cavities molded in to begin with.

A couple other suggestions:

Put at least thin tape on the front, sides and bottom on the recoil lug. You can bed it with no clearance but in my experience it's 100% a bear to remove and install it you bed it with a 1:1 fit and you can even damage the stock or bedding removing or installing the action if you're not careful.

Use bedding compound even in places where you think you don't need it. I have found Johnson's Paste Wax to be as good as anything and it's cheap in huge quantities. If you buff it into the metal with a micro fiber cloth you will end up with a super smooth, glass like finish to your bedding.

Get some modeling clay or similar from the general store or craft store or wherever and use this to fill in any little voids in your action... Trigger pin holes, gas vent hole etc. Can be really difficult to remove bedding here and if you get it somewhere critical like the bolt raceway or lug abutments you're in for a bad time.

Chisels, gouges, dental picks, and scalpels work great for removing hardened bedding and squaring up bedding. A small milling machine is awesome but you can do a fine job with hand tools.

Q tips or cleaning patches soaked in acetone/degreaser are great for removing excess bedding if it flows over when you tighten the action down (much easier to clean it up before it sets)

You don't have to bed the whole barrel channel and relieve it. I like to use 10 mil tape, about an inch to an inch and a half, and cut it to wrap around the chamber portion of the barrel. You only have to bed this portion and it will naturally float the rest of the channel. While you're prepping for the bedding, you can also wrap the barrel in layers of tape until it just touches the sides of the stock. This will help keep the barrel centered in the channel. Otherwise you run the risk of bedding the action ever so slightly crooked in the stock (you'll see an uneven gap in the barrel channel)

Bedding is 80% preparation. Triple check you have done everything right. Applying the epoxy and tightening the action down is the hair raising part of it and you don't have a ton of time to work, but it's more than enough time than you need and the success here is largely determined by your preparation in advance.
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Old November 25, 2020, 11:04 PM   #4
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This stock also has the large cutouts with polymer ribbing down the forearm. The stock is pretty rigid as it sits. My intention with bedding the entire barrel channel, was to stiffen the fore end more than it is already.

I ended up buying
https://www.midwayusa.com/product/1406321274?pid=661230
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Old November 26, 2020, 08:02 AM   #5
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I've done about a half dozen Tupperware stocks--I do what Dakota does, use marintex in the forend channels, but the marinetex or epoxy alone will not be enough to take the flex out and I usually embed an aluminum rod or plate of some sort into the epoxy in the foreend. When you sight in with a cheek weld, you'll notice the sight picture will tend to go up and down--that's because their is a hollow void in most of these stocks where the grip meets the rear stock area--which is also usually a void or filled with a couple of pieces of styrofoam. I fill em with envirotex. Nowadays I just buy wood stock replacements and do the whole pillar/bedding routine since there's no way a tuppareware stock will ever be as good as a wood stock IMO, I'm not thrilled with the other composite type stocks either. Wood or aluminum chassis is what I do.

I used that stuff once and only once--'nuff said.
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Old November 26, 2020, 10:32 AM   #6
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The 2 Savage Tuperware stock i have are action bedded using Devcon. Both came from the factory with pillars.
I tried the Acraglass route and didn't like it. Too soft. Both the regular and the gel type.

On my Stevens 200 i used lightweight Bondo to fill in the voids and help stiffen up the forestock.
Still some flex, but not nearly as bad as it was. Didn't add too much weight either.
Cheap & readily available. Easy to work with also.

On my 111 i cut channels in the ribbing, and epoxied a carbon fibre arrow that was cut lengthwise into each side.
Added very little weight. Still flexes, but again not as much as stock. The bondo stock is stiffer, but weighs a little more.

With anything your using in these stocks, prep is the key.
Sanding, locking voids help with grip. I degrease using spray ether (aka starting fluid).
I also found that the spray "adhesion promoter" (found at any auto parts store with the paints) helps.
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Old November 26, 2020, 11:42 AM   #7
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Brownells Steel-bed compound is hard and much better than Acraglass, IMHO, just not as cosmetic in some instances. Bisonite is the one most popular with M14 shooters. I've used both and both do well with actions that bang things around a vibrate a lot, as the M14 and Garand do. I just have no faith in them adhering to plastic because of plastic's greater flexibility. The Flexane rubber bedding approach was popular with some for awhile. Champion Shooter's Supply (now gone, alas) used to sell it for the purpose. The idea was to absorb some of the initial recoil like a spring while the bullet was still in the barrel and before passing the energy to the stock.

Quote:
Originally Posted by kilotanker22
This stock also has the large cutouts with polymer ribbing down the forearm. The stock is pretty rigid as it sits. My intention with bedding the entire barrel channel, was to stiffen the fore end more than it is already.
The ribs you refer to are what my old Savage 10FP (pre-accustock and pre-accutrigger model) came with. It was so flexible that with a Harris bipod on the front, recoil made it slap the barrel hard enough to wear the bluing off in one spot in 100 rounds or so.

The cure suggested to me was to angle-drill holes in the stock ribs on either side of the center to accommodate a couple of scrap carbon fiber arrow shafts. Apparently broken ones work and can be got for free. Those holes would be oblong, so you would sandpaper-roughen the shafts at the pass-through points and epoxy-glue them in place by getting JB-Weld or bedding compound on both sides of each rib hole so the hardened compound would lock the shafts in place.

I bought a different stock before I got to that work, so I haven't tried it myself, but the idea seems reasonable. It would add a lot of rigidity without the increase in weight that filling the cavities between the ribs would incur.

Here's a thread that includes descriptions of a number of brands of bedding material.
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Old November 26, 2020, 02:19 PM   #8
T. O'Heir
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Might be a better idea to pillar bed it. Literally lifts the barreled action out of the stock altogether. Vs making the barreled action and stock more cohesive.
Bell and Carlson supposedly makes the stocks for Remington.
"...bedding the entire barrel channel..." Is not a good idea. Floating gives no guarantee of anything but it needs space to "float". It's one of the things you can try without a lot of fuss though. Putting a pressure point back in is easy.
Steel-bed compound is what JB Weld is. Has powdered metal in it vs the powdered fiberglass of Acraglas.
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Old November 26, 2020, 02:34 PM   #9
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I think "bedding" the forestock was the wrong phrasing.
Aside from using "bedding" compound, Kilo is actually looking to fill the large open spaces, with the goal of making it stiffer.
Much like i did with the Bondo.

Nathan Forester of Ballistic Research developed a "stock stabilizer".
An epoxy compound meant to stiffen the Tupperware stocks, without adding a bunch of weight.
But he's in New Zealand and i don't know of a distributor in the US.

The only person i know of that actually beds the full length of the stock to the barrel is Melvin Forbes of NULA (New Ultra Light Arms).
In talking with him, the full length bedding does not work with the plastic stocks.
He claims you need a stiff composite stock to begin with for the full length bedding to be effective.
Judging from my Forbes 24B, he's got something there! Lol
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Last edited by std7mag; November 26, 2020 at 02:40 PM.
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Old November 26, 2020, 02:53 PM   #10
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IMO,it would be good to understand there is a big difference between "tupperware" injection molded polymer stocks

And composite epoxy/glass/kevlar/graphite/foam/etc stocks

Big difference!!

I don't know that I would waste my time tryng to bed a molded polymer stock.
Probably do more harm than good....Though there MAY be exceptions.

Epoxy won't stick to tupperware.

On ribs in ,molded plastic parts.A fundamental of molded part design is uniform wall thicknesses.
A whole bunch of heat goes into melting the plastic. We who built molds have a lot of experience drilling through maybe 10 inches or more,a lot more,of 4140 steel with a 1/4 in drill for water lines to make the mold's cooling system to suck that heat back out of the mold.

Polymers conduct heat very slowly.If you design a molded part with a thicker section....two things.

Cost .Press time is money. Thick sections take time to cool. 30 seconds gate to gate makes more money than 2 minutes gate to gate

And shrinkage problems. Moldable thermoplastics typcally shrink somewhere between about .006 to .024 per inch as they solidify. The heat goes into the mold steel,so a skin of polymer solidifies first. While its not perfectly true,for illustration,lets say the polymer that as solidified is done shrinking.And it has its shape,so we don't want it to move.

But as the thicker plastic cools,and solidifies,the shrink WILL happen.And its drawn from the material that is not yet solid.
So,you get stress,warp,sink,and voids.

Ribs are a means to engineer material into,or out of a design in a way that allows for uniform wall sections.

Last edited by HiBC; November 26, 2020 at 03:17 PM.
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Old November 26, 2020, 04:11 PM   #11
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Not worth the effort IME. Who cares if the forend is flexible. As long as it doesn't touch the barrel it doesn't effect anything. I've found the best approach is a generous free float.

I have some rifles in McMillan stocks, some in factory wood, and some in cheap tupperware stocks. I can squeeze the stock near the end with one hand and make most all of them touch the barrel. The only ones I can't are the Tikka's. But under normal use none ever touch the barrel and never effect accuracy.

I've never noted any measurable difference in accuracy when bedding the action of ANY synthetic stock either. The practice of bedding stocks was important when everything was wood. Wood naturally expands and contracts as atmospheric conditions change. Having a layer of synthetic material between the wood and action helped reduce the effects of the stock expanding and contracting. Making the entire stock synthetic pretty much eliminated the need.

Some synthetic stocks have a somewhat sloppy fit and some guys who are anal about such things want a tighter fit which bedding can accomplish. But for the vast majority of shooters it offers no measurable gains in accuracy. If getting that last 1/10 MOA out of a rifle is important then go for it. But I don't see it making any difference with a $69 stock.
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Old November 26, 2020, 04:41 PM   #12
dakota.potts
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Just to expound upon some above sentiments - while one is already taking the rifle apart to bed it, that may be a worthwhile time to upgrade to a better stock. As far as molded polymer goes, I've had good luck with the Magpul Hunter stocks. I believe they're aluminum pillar bedded too (don't quote me on that).

Of course for maximum rigidity something like composite, fiberglass, or even an aluminum chassis is about as good as it gets. But often the price difference is significant.
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Old November 26, 2020, 05:23 PM   #13
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I've never understood why some people think the first inch or more of the barrel in front of the receiver has to be bedded.

Depending on the forend stiffness and how the rifle's held, the amount of force on the barrel it applies will vary. So will the direction bullet's shoot.

If there's clearance, the external force on the barrel will always be zero. Regardless of whether or not you shoot your stuff precisely enough to see the results
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Old November 26, 2020, 10:03 PM   #14
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Quote:
I've never understood why some people think the first inch or more of the barrel in front of the receiver has to be bedded.

Depending on the forend stiffness and how the rifle's held, the amount of force on the barrel it applies will vary. So will the direction bullet's shoot.

If there's clearance, the external force on the barrel will always be zero. Regardless of whether or not you shoot your stuff precisely enough to see the results
My only goal when fooling with tupperware was to keep the sight picture from flexing up and down.
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Old November 26, 2020, 11:50 PM   #15
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Bart, I hadn't really thought of it that way.

Today I shot some pretty good groups with it after lapping the bore. All groups were sub moa so I am rethinking if I should even bother to bed this stock.

I honestly wouldn't mind keeping this rifle about the weight it is now, 7.8 Pounds ready to hunt. Maybe the purchase of a carbon fiber stock (Stocky's VG2) should be in order. At 28 oz I can't imagine that it is much heavier than the oem stock.
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Old November 27, 2020, 10:41 AM   #16
Bart B.
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Quote:
Originally Posted by stagpanther View Post
My only goal when fooling with tupperware was to keep the sight picture from flexing up and down.
Hold the rifle still while you stop breathing and the sight picture will remain stable.

Most of us can hold fairly still with sharp vision for 15 seconds after stopping breathing.

One can reinforce the fore end to make it stiffer but it still has a hinge point where the barrel touches the receiver. It may not bend itself but can put pressure on the barrel.

The dollar bill test results are valid only when done with rifles in shooting positions with normal external forces on the rifle. But the barrel and stock fore end can still bend enough during barrel time to make contact so some clearance is needed.

As the barrel diameter increases as it heats up, totally free floating ones have the same external forces on them all the time; zero.

It's common knowledge that the barrel forward of the stock fore end should not touch or rest against anything. What about the barrel behind that place?

Last edited by Bart B.; November 30, 2020 at 04:31 PM.
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Old December 1, 2020, 03:08 AM   #17
kilotanker22
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These Remington 700 synthetic stocks are made from "lightweight, fiberglass reinforced polymer although they don't say what polymer they are made from.

Being that they are glass reinforced, I will use a torch to heat the plastic to help it stick. I knew it was better than a tupperware stock sinc after floating it still does not make contact with a loaded bipod
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Old December 4, 2020, 09:36 AM   #18
Bart B.
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Quote:
Originally Posted by T. O'Heir View Post
Floating gives no guarantee of anything but it needs space to "float".
Free floating barrels guarantees they'll vibrate the same way for every shot fired while bullets go through them if the rifle is held the same way each time it is shot and all the part's dimensions are correct.

Last edited by Bart B.; December 5, 2020 at 01:50 PM.
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