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Discussion Starter #1
I am hoping this is the right location for this question.

I have been working on and off on a rifle stock design for myself. I had glued a piece oflighter color walnut to the walnut stock so I could carve the forend. It fell off while I was working on it. I'm not a wood worker and this is a first stab at doing a gunstock. the adhesive I used was a Gorilla glue made for wood.

Can anyone tell me what I should have been using. The two pieces were mated perfectly flat together.
Are these parts assembled with a biscuit or dowel type setup?

I'd appreciate any input on this.
 

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Gorrilla glue is great as long as its clamped, but I use common Tite Bond. Epoxy makes a finish-proof joint that will always show.
 

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Discussion Starter #5
Didn't think about the epoxy in the joint.
The Gorilla Glue didn't seem to cause an issue other than it didn't hold. I have a very good tight seam when glued.
Thanks Jbeld
 

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Gorilla glue is an expanding poly urethane that forms hexagonal 'cells' that look like honey comb under a microscope. Wipe the wood with a wet cloth, apply the glue and clamp with a metal clamp (not elastic). The glue forces its way into even dense French walnut a surprising distance as it cures but the joint will spread if given a chance.

For fore-end tips of ebony, I suggest drilling both sides and using a section of SS threaded rod as re-enforcement. That is one place I use epoxy glue after spraying the ebony with brake cleaner several times to get the waxes and oils out of the top layer. They should also be clamped until cured.

Here's the late Maurice Ottmar's fore-end tip on the #9 ACGG rifle.
 

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.

I use a 2-part epoxy, into which I've mixed a little sawdust from the stock I'm working on (obtained via drilling a small hole under the buttplate).
When the epoxy cures, it should be invisible to someone who's not looking for a joint there.

I NEVER adhere two perfectly flat pieces of wood together w/o first drilling several small/short holes in the opposing flats, at various different angles, so the adhesive of choice will lock both surfaces together (after curing), giving the joint more strength.


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Discussion Starter #8
Ok how would you prevent the two pieces of stock from adhering to the clamping device.
Such as a release type agent or material that is not adherent to glues? If a chemical it would have to be non-invasive to the wood.
I understand you try to not load the adhesive on the parts so that is runs beyond the edges of the wood but that is not always preventable.
My fore end has a Schnabel type carving to it and so I would have to have a compressing material that would not damage the wood but allow for solid clamping. I would consider the closed cell foam I have on hand for that but have to have a way to keep it from sticking to the wood.
Whatever release agent I would use would have to be non-invasive to the wood pieces.

I had carved the fore end while it was originally glued onto the stock, but as I mentioned earlier the Gorilla glue did not hold. I had wetted then glued and clamped the two pieces originally when the fore end was just a square block. It seemed to have worked but after I had the fore end carved the stock got knocked over and hit a cross member to my worktable and the fore end came off. Surprisingly the stock and fore end were not damaged at all.
 

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When I have a job that calls for holding something fragile really tight, I make a 'cast' out of Bondo. Use Saran Wrap between the part and the Bondo. You could make a small box, fill it with Bondo, spread a layer of Saranwrap and lay in the carving. In about an hour you have a solid clamping surface that perfectly transfers to the part.

I can't figure your failure out. It failed through sheer and that points to a wide joint. Do you see bubbles in the glue joint?
 

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Discussion Starter #10
Yes, there were very fine bubbles in the glue. I evidently didn't have as tight a clamp as I should have. The block being square and the stock was a semi-finished piece I had picked up for thirty bucks to try out my ideas.
This is a learning project for me, not a finished product. I just want to try and get it as good as possible for when I attempt the real stock. That way I figure out the methodology before trying a finished stock.
 

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That's a great plan!! Look at what it takes to make plywood to see how much pressure it takes to make a good joint with certain kinds of glue. I'm not an adhesives engineer, but my understanding is that the 'milk glues' like Elmers, TiteBond and Carpenters don't expand on curing like the old WeldWood and the amber-colored Gorilla glue.

I was making some kind of fixture and had several pieces to glue and clamp. The last two werent all that important so instead of walking to another clamp I just laid something about 5 lbs on top and left it overnight. The joint was brittle and broke right away. There were bubbles in the varnish-like joint. After the job, I broke one of the other parts but it failed in the wood, not the joint. I ground off the remains and sectioned some to look at close. The best joints have a honeycomb structure that runs from one piece of wood to the other without any 'honeycomb' made of just glue. I was impressed with it. I see now there's a white Gorilla Glue. I don't know what that's all about.
 

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Discussion Starter #12
Hi Jbelk;
Like you I'm not an adhesives expert. I haven't seen the white Gorilla Glue. I do know that that Gorilla glue is an expansion glue meaning it is designed to fill a space to create adhesion where there is a void. That is why it will form what you see as a honeycomb. It is not meant to be a joint in and of itself though. it is not strong enough. The resins like Acraglass were designed for making their own solid joints.

I had the idea of making small shallow drill holes and using Gel Acraglass as a filler and then another glue like Tite Bond around the outside of the joint. Once the Acraglass was set it would not come apart. The other Glue would act as a kind of filler and adhesive and not show when stained. Anything stronger than that would involve using a threaded metal rod like you suggested. I just never do well in aligning the holes between the two pieces.
 

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Gorilla Glue likes to be really wet-as in sloppy, wringing wet! It sounds to me like you didn't run it wet enough! As Jack said, use a solid clamp, as the stuff has a hydraulic action when curing, and will occupy about three, or four times it's original size, given the chance! It took me a while to realize just how sloppy it needed to be in order to work right!
 

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Discussion Starter #14
Just thought of a release agent to use between a glued item and either a form such as the Bondo or a clamp.
WAX!
it won't adhere to the glue can be spread thinly and will release and clean up from the wood.
 

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Hi Jbelk;
Like you I'm not an adhesives expert. I haven't seen the white Gorilla Glue. I do know that that Gorilla glue is an expansion glue meaning it is designed to fill a space to create adhesion where there is a void. That is why it will form what you see as a honeycomb. It is not meant to be a joint in and of itself though. it is not strong enough. The resins like Acraglass were designed for making their own solid joints.

I had the idea of making small shallow drill holes and using Gel Acraglass as a filler and then another glue like Tite Bond around the outside of the joint. Once the Acraglass was set it would not come apart. The other Glue would act as a kind of filler and adhesive and not show when stained. Anything stronger than that would involve using a threaded metal rod like you suggested. I just never do well in aligning the holes between the two pieces.
It will not only fill a void, it will PENITRATE the pores and grain, if used WET enough, making a very strong joint!
 

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.....

Can anyone tell me what I should have been using. The two pieces were mated perfectly flat together.
Are these parts assembled with a biscuit or dowel type setup
?
......
Virtually all glues will work. Which is the only one needed for a lifelong bond? Yellow aliphatic resin (Titebond or any yellow glue). If you'll be dipping the stock in the lake for extended periods from time to time, then Titebond II is all that's needed.

Properly prepared joint. Properly applied Yellow glue. No biscuits - no dowels. Done.

Want to use Gorilla glue, hide glue, epoxies w/wo resins, etc.? Dowels or biscuits? Great! But..........NONE of them will give you any better bond than yellow glue.
 
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I don't like your mixing of adhesives. Life is complicated enough as it is!

There are adhesives and there are fillers, both made of epoxy. When epoxy is thick and opaque it has fillers in it. Some have fillers that are round, like Acragel, or foamy like Bondo. Both with adhere, but their jobs are to fill.

Clear epoxy is great if there is no gap. So is Gorilla Glue or white glue or even hide glue, still used in guitars. When there's a bad fit its another story. Many make the mistake of thinking a bad fit well clamped will stay glued. Not always!!

I started making knives in 1970 and did quite a bit of research on the 'perfect epoxy' for my use. I settled on Conap Easypoxy, K-22 Black. I've used it for nearly fifty years in making knives without a failure, but the joints are very tight with no stress anywhere then clamped overnight. When using irregular material like this sheep horn is when I make the bondo cast I wrote about. I do it on a piece of 1/4 in. thick flat steel bar. Just smear Bondo on the bar, lay on Saran wrap and then the piece of stag or sheephorn to make the cast.

This knife actually has six handle parts. There is a .025 black fiber liner next to the tang, then .062 brass and then the sheep horn scale on each side. The "Christmas Tree" file work in the tang is filled with Conap epoxy from the original gluing (1983?).
Conap has a flat fiber as a slight thickener and makes incredibly thin joints very strong.
 

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Just thought of a release agent to use between a glued item and either a form such as the Bondo or a clamp.
WAX!
it won't adhere to the glue can be spread thinly and will release and clean up from the wood.
Yup, wax has been my buddy for many years! If you get your hands dirty, it will clean them, to an extent-as a bonus! Just don't get it on anything you want to stick to something else!
 

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Didn't think about the epoxy in the joint.
The Gorilla Glue didn't seem to cause an issue other than it didn't hold. I have a very good tight seam when glued.
Thanks Jbeld
Gorilla glue expands as it sets. If the proper amount is not properly applied and clamped, it will not form a solid joint. These Gorillas, epoxies, etc. are specialty glues. They don't belong in a walnut workshop. This is where yellow glues shine.

IF a quality stockmaker were building for you a walnut stock... and say for example he had to glue two pieces together (let's just say IF he had to), he would use yellow glue and no other (possible exception? white glue). Then he would shape, sand, seal, and finish your rifle stock before sending it to you.

If he we using certain exotic hardwoods for the stock, he might use a different glue, although an oily hardwood, properly prepared, would still be fine with Titebond II or similar.

ON EDIT: Even yellow glues need a tight joint (as you said yours had) and the glue must be spread thinly and evenly. I use an acid brush dipped in water and wrung out with my fingers. Too much or too little glue of any kind will form a weak bond, as will too much or too little clamping pressure.
 
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Gorilla glue expands as it sets. If the proper amount is not properly applied and clamped, it will not form a solid joint. These Gorillas, epoxies, etc. are specialty glues. They don't belong in a walnut workshop. This is where yellow glues shine.

IF a quality stockmaker were building for you a walnut stock... and say for example he had to glue two pieces together (let's just say IF he had to), he would use yellow glue and no other (possible exception? white glue). Then he would shape, sand, seal, and finish your rifle stock before sending it to you.

If he we using certain exotic hardwoods for the stock, he might use a different glue, although an oily hardwood, properly prepared, would still be fine with Titebond II or similar.

ON EDIT: Even yellow glues need a tight joint (as you said yours had) and the glue must be spread thinly and evenly. I use an acid brush dipped in water and wrung out with my fingers. Too much or too little glue of any kind will form a weak bond, as will too much or too little clamping pressure.
Agreed, but I glue other things around here besides gunstocks! I like it for bonding work bench problems that sometimes happen with the force applied by reloading presses, causing split, or cracked boards.
 
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