epoxy problems

[back pocket]

Good day! I am using bubinga for the sides of some slip joints, and am having some problem with acraglass holding on brass liners. Some hold, some don't ...out of the same batch of glue-ups. I have roughed up the brass to give some mechanical holding area. The brass is clean before gluing up and clamping. Is bubinga an oily wood that prevents better results? Any suggestions? Thanks, Tony!

[DaveL]

Adhesives are a constant item here and there was a very good thread on the glue wars, hand on...

[Ray Rogers]

Ya, bubinga is oily and that could be a problem. Brass liners can be thin and flex a little and that can be a problem too.

AcraGlas is great stuff but no epoxy should be relied on to hold scales in place without the help of some kind of mechanical fastener (pins, screws). Since you didn't mention using a fastener I thought it might be worth mentioning......

[chiger]

Ray is right Tony. You should probably be using hidden pins of some kind if you aren't.

It's going to be hit and miss with woods like bubinga. You might try using some alcohol on the wood before you glue it to clean off some of the resin. Or even a little pass or two with a propane torch and then a cleaning.

Might work. Oh, and make the mechanical holding areas in the wood bigger and irregular.

chiger,

[Don Robinson]

Yep, Ray is right. No pins, no hold, no matter what adhesive you use.

Besides using thru pins on all scales, if your scales are thick enough drill thru the liner part way into the scales from the back side several times. When the epoxy is applied it will flow into these blind holes and thru the liner, creating an epoxy rivet.

[DaveL]

I use Loctite 330 Depend, some like and some don't. But, as I recall, Loctite was the winner in the glue wars on here before. Yes, a pin through the liners is almost, if not so, a must.

[back pocket]

I am using one thru peened 1/16th brass pin at the front of my liner to just hold to liner only and the two 1/8th through brass pins at the spring pivot and spring base to hold assembly together...3 peened pins total to hold scales on. I read the glue wars and thought Acraglass was the ticket, but did need mechanical holding also. Don, good idea on the epoxy rivet...I'll do. Chiger , showing my dumbness, are the hidden pins as I think of the epoxy rivets.. simply drill from back of liner partially into thick scale , place a short not thru pin,and glue up? I will use alcohol to clean liners. I was using Simple green, I think. And I will try the torch also. Thanks for all the advice! Tony!

[Don Robinson]

When you make epoxy rivets, countersink the holes on the insides of the liners. Stronger, and less chance of pulling the epoxy rivet thru. It's a good idea too to use a Dremel or something and really rough up the liners and the insides of the scales. That way, when you clamp the assembly together for curing, the epoxy can't all squeeze out like it does with a smooth flat surface. If you have room on the scales, make a hollow along the length of the scales for epoxy to bond to instead of being squeezed out.

[back pocket]

Thanks, Don...common sense ideas...wish I had thought of them!

[chiger]

Yep, you've got it Tony.

I actually like to tap the tang and use machine screws, without the heads of course, and then dremel large irregular pockets to give the glue plenty to grip.

Not sure you can tap your liners, but peened pins would probably do ok.

chiger,

[Don Robinson]

When I make slipjoints I drill the pin holes thru the liner and scale, then remove the scale and c'sink the holes on the inside of the liners. Then I make a short pin, hold it with pliers on an anvil, and use a 1/4 lb. hammer to peen the one end. This peened end fits the c'sink in the liner. The end sticks up a little, but a Dremel will remove it down to flush.

The epoxy then will hold the pin in place without the need to peen the scale end of the pins. I just finish them down flush with the scale.

By the way, thanks for the thanks. That doesn't happen often. You're quite welcome.

[Gary Mulkey]

I agree with the mechanical fasteners. Also, one thing that will help adhesives is to rough up both surfaces with a coarse belt. This will give the adhesive more surface area to hold onto.

Gary

[back pocket]

Gary, I was roughing up maybe with too fine of a grit of paper....I will go more coarse next time , Thanks, Tony!