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Finally Getting Somewhere - and a question about gluing.
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=28856		 Page 1 of 1
Author:  Stuart Gort [ Tue Aug 31, 2010 11:10 am ]
Post subject:  Finally Getting Somewhere - and a question about gluing.
viewtopic.php?f=10106&t=28855

I'm hoping some of you will notice the glue line between the layers of the top plate and offer any suggestion as to how this might be avoided.

The glue lines get wider as the surface becomes shallower as one might expect, but I'm looking at a glue line that is a little too noticable. When the outside surface is cut (the one you will actually see) the wood will be reversed so the glue line will look better with the bloodwood on top of the toasted maple. But then the curly maple is going to be on top of the bloodwood and I expect the glue line to be more apparent there.

I'm using lots of pressure to sandwich the raw, flat panels together prior to cutting these plates. My theory is that too much pressure might be forcing epoxy too far into the wood. Also, the epoxy is amber....which may be exacerbating the situation.

If anyone has an obvious solution for this issue....I'd be greatly appreciate the advice.
Author:  bluescreek [ Tue Aug 31, 2010 11:24 am ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Can you use HHG ? I think the glue line may be less noticable . Epoxy does have a thick signature as compared to glues. Interesting , as I wanted to do a chambered tele. I was planning on placing a mic in one of the chambers to see what that would sound like .
Author:  Stuart Gort [ Tue Aug 31, 2010 11:32 am ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
bluescreek wrote:
Can you use HHG ? I think the glue line may be less noticable . Epoxy does have a thick signature as compared to glues. Interesting , as I wanted to do a chambered tele. I was planning on placing a mic in one of the chambers to see what that would sound like .


How long might HHG stay open before it stops flowing?

My glue jig is pretty effective and vesatile but it takes a long time to finally apply all the pressure. In that time the glue needs to remain open so excess glue can be squeezed out. Since there is a lot of surface area on these panels, and since I need to glue both panels prior to gluing...I spend a good deal of time just spreading out a glue. Do you thinhk hide glue will stay open that long?

On this top piece there are three discreet layers which I glued all at the same time. The first thing to try is probably to only do one at a time.

As an idea the mic in the hole idea is great. A prototype would be cool that allowed one to change the position of the mic in the chamber. Otherwise it might get placed in a node and you accidently miss the sweet spot. F-holes would help here. laughing6-hehe
Author:  Daniel Minard [ Tue Aug 31, 2010 12:11 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
If what you are seeing is epoxy penetrating deep into the fibres, epoxy filler might neutralize the effect by "staining" the rest of the piece in a similar fashion.
I have seen a similar effect on a laminated maple neck. Once carved to shape, the glue lines were clearly visible. After filling, everything blended together nicely.
Author:  Fred Tellier [ Tue Aug 31, 2010 12:30 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Try fish glue, it dries almost clear and acts just like Hide as it will pull the joint together as it cures and has lots of working time. Some woodworkers use rub joints with hide glue when joining thick wood, you can also heat the parts when using hide which will extend the working time. Even titebond extend will give you lots of time and should not show as much as the epoxy.

Fred
Author:  Mike Collins [ Tue Aug 31, 2010 12:58 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
I'm with Fred!
Fish glue has allot of open time and is much easier to use then HHG.
No mixing,heating-etc...
Plus it seem to have a very long shelf time.

Mike
Author:  WaddyThomson [ Tue Aug 31, 2010 1:23 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Fish glue clean up is a little more sticky than with hide glue, but it does wash off.
Author:  Stuart Gort [ Tue Aug 31, 2010 4:18 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Do you guys think that Titebond Extend might have the same "drawing together" effect as fish or hide glue? Can anyone explain this effect more? I assume with fish glue we are drawing moisture into the wood and simply losing volume as it cures. In this respect, Extend might be exactly the same, losing water into the wood. I notice my neck laminates glued with Titebond show no visible glue....even under magnification. Pffft....I should have thought about that prior to gluing the body.

Also, will fish glue require a chemical, pre-glue prep with solvent prior to gluing bloodwood?
Using a PVA I think it's probably a good practice to do so. With epoxy it's not necessary...though it's a minor issue.

I had a long conversation will a guy named Hugh (former Gibson employee) at Titebond about this project today (great customer service - btw) and he mentioned the Extend as a potential solution. This appleals to me because one can tightly control the viscocity of Titebond. 5% water has no effect on strength but cuts the viscocity in half. Hugh said that thinning with water will also extend its open time a little.

I'm going to pick up both fish glue and Extend tomorrow.

You guys are a GREAT reference!! Thanks!
Author:  Mike Collins [ Tue Aug 31, 2010 4:54 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
http://www.norlandproducts.com
It needs nothing added to the wood or glue to bond.

read all about it !
mc
Author:  Fred Tellier [ Tue Aug 31, 2010 5:49 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Titebond Extend is just a slower curing version of the original product, I use it for wood bindings as it gives me more working time though my next binding will be fish glue.

Fred
Author:  Parser [ Tue Aug 31, 2010 9:57 pm ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Titebond is probably the easiest thing to deal with. The one advantage of the polyurethane glues like Gorilla glue is that when you sand along the glue line (as you might do with an oscillating spindle sander), you won't get a glue line building up on the sanding drum. PU glues turn into dust when you sand them while PVA glues like titebond melt & deposit on the sandpaper..

The only time I've seen epoxy used instead of titebond (or even elmers carpenter glue) is with oily wood like cocobolo.

Those shapes look cool & the work looks really clean...nice work! I like how you have the wire paths milled into there...that's often overlooked & should really help make assembly go more smoothly.

Best,
Trev

PS - you can still end up with undesirable glue lines with titebond. The trick is to clamp all along the periphery. If you're gluing up a stack of bodies at once (as some factories do), you may have to make a thin "donut" shaped piece of wood to put in the stack in between the bodies. This keeps all the pressure at the edge where you really want to minimize your glue lines..
Author:  Stuart Gort [ Thu Sep 02, 2010 10:29 am ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
I was hoping that Woodcrafter would have some fish glue but they didn't.

I went online to find some but there are several different kinds.

Does someone have a specific recommendation for a brand name and type of fish glue?
Author:  Fred Tellier [ Thu Sep 02, 2010 11:30 am ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
I got mine from Lee Valley here in Canada.

Fred
Author:  SteveSmith [ Thu Sep 02, 2010 11:36 am ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Zlurgh wrote:
I was hoping that Woodcrafter would have some fish glue but they didn't.

I went online to find some but there are several different kinds.

Does someone have a specific recommendation for a brand name and type of fish glue?


Lee Valley sells the Norland fish glue which is good stuff. If you haven't used it before using fish glue is a lot like using titebond as far as spreading, clamping, and cleaning. I leave fish glue clamped overnight.
Author:  WaddyThomson [ Thu Sep 02, 2010 11:55 am ]
Post subject:  Re: Finally Getting Somewhere - and a question about gluing.
Don't forget to stir the fish glue.
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