MIMF

When laminating sides, i've used Titebond and epoxy. the former leaves a side with more spring than i'd like. the later is a mess. I'm curious what people are using.

Kary,
Have you tried polyurethane glue? It has up to a 20 minute open time and is anaerobic. I'd also try resorcinol. I think both emit nasty fumes so ventilate.

thanks David,
i've used polyurethane before and don't like the mess and cleanup from the foaming. funny you should mention the resorcinol. I just bought some plastic resin glue that i'd like to give a try, but winter temps have hit and keeping the glue up above 70 degrees (required for these glues) while ventilating the fumes is problematic in my garage. i may have to go back to TB and try the plastic resin come spring time. maybe fish glue (?).

The "trick" with poly glue is to use a lot less of it than you're used to using. Just spread one thin layer on one surface, and unless your shop is very dry, you don't need to wet the surfaces, which only makes it foam more aggressively. Use wax paper to wrap the veneer while clamping.

Don't attempt any cleanup until the foam has completely cured! Once cured, just cut-off any excess foam.

Re polyurethane clean-up there's a brief period after the initial cure when the foam becomes very brittle and it's very easy to scrape it off. It seems to toughen after that making it a lot harder to deal with.

I am fairly new at lutherie however I have used Titebond for laminated sides in a form with a caul and urea formaldehyde for sides in a vacuum bag on a form...both have turned out very well.
I am building in the gypsy style at present.

Regards,

Dj

Jim Ham (wonderful upright bass maker in Victoria, Canada) laminates his ribs/sides in vacuum.
I did a workshop with him a few years ago and he described this technique in some detail.
He uses a urea formaldehyde glue and accelerates the cure with heat inside the laminating form.

Several of the guitar makers that laminate, including Somogyi (according to his book, at least) are using West epoxy.

I would stray away from using Titebond - that much water introduced into thin stock seems like a recipe for instability.
It's a really big glue joint.

Cheers!
Martin

I started an identical thread in late February 2012 - "Glue for Laminated Sides". You might find some useful ideas and opinions there.

Alan, thanks for the reference (and to everyone for jumping in). I'm waiting for an order of Unibond 800 glue to arrive. see how it compares with PVA and epoxy.

I've used the Better Bond brand of veneer glue to laminate sides. It came in different colors (light, medium, dark), and the light was pretty thick, sticky stuff (if it was Titebond I'd have thrown it away---suspecting it was old). I wasn't able to get a large area rolled out without it ending up a pretty questionable-looking bed of gooeyness, so I used the medium instead. Just the opposite problem with it. It was like watered-down Titebond, and by the time I got everything rolled out, assembled, and clamped down, I had the sneaking suspicion that I was going to have some glue starvation. Which turned out to be true.

I asked the vendor about it and he told me that was the proper viscosity for those glues, so I don't think I got a bad batch.

I tossed them both and went back to Titebond.

I'd be curious to hear how the Unibond 800 works for you.

I just read through a discussion on unibond 800 over at the woodweb forum. It sounds as though you really need to mix the stuff thoroughly using a power mixer, let it sit for a while and mix it again. Any undissolved crystals can discolor the wood on the outside if the veneer layers are thin enough. They now sell a powdered additive to block bleed through.

I've used Unibond 800 many times. The first time I used it I did not get the powder mixed in and ended up with a lumpy gravy consistency. But after that I just made sure to mix it well until all the lumps are gone. A powered mixer is not required.

The additive does lessen bleed through which can be a problem on "leaky" veneer.

If you don't want to use or have a powered blender, then use one of those whisk stirring things that your wife or whoever cooks your food has around the kitchen.
"If the cream sets out too long, you must whip it...."

I've used Titebond (too much hydration) and Weldwood plastic resin glue (better but still some hydration). I now use WEST epoxy. Much better, not as messy as I had expected.

just laminated two sets of sides. one with Unibond 800 and the other with Titebond. Unibond is less convenient due to its mixing and temperature requirements. it is also pricey, considering its short shelf life. Its long working time made laminating a breeze. Titebond was much more convenient, but with a much shorter working time.

No appreciable difference is stiffness/flex between the Unibond and Titebond sides.

I made my recent ribs from a 3-ply lamination: inner (poplar) and outer (maple) plies 1/16" thick each, and sandwiched between was a single piece of 1/64" baltic birch plywood, oriented (grain-wise) at 90 degrees to the inner and outer plies. No need to worry about cracked sides. If you spread your glue with a small ink brayer (roller) it all goes pretty quickly.

I use west system epoxy. I use the plastic "backing" from cheap foam brushes to spread the epoxy on the sides. A little goes a long way, but you do want to use enough. I use wax paper on both sides of the glueup and don't worry about bleed through because I also pore fill with the same epoxy. The trick with epoxy is to keep it off your hands - then it doesn't seem quite so messy.
I also dry the veneers as dry as practicable. This seems to make a more stabile lamination. I think it helps the epoxy fill the voids more throughly and leaves less space for water absorption.

I'm going to try fish glue next. My two lams are 1.8 mm each, so I don't need to worry about the water issue on thin veneers. Long open time and inexpensive. Also, not temp sensitive while setting like the plastic resin glues.

Clay Schaeffer wrote:I use west system epoxy. I use the plastic "backing" from cheap foam brushes to spread the epoxy on the sides. A little goes a long way, but you do want to use enough. I use wax paper on both sides of the glueup and don't worry about bleed through because I also pore fill with the same epoxy.

Please tell me about your pore filling with epoxy. I just laminated some sides with curly maple with West System and got lots of bleed through. I then tried coating the finished sides with the same epoxy hoping to negate the bleed through, but it didn't work - bleed through areas are still way darker than the non-bleed through just surface coated with epoxy. Do you have to coat/sand/coat again? What about sanding through the thin veneers?
Any help appreciated.

Hi Mark,
I generally work with more open grained woods when I laminate sides. My usual method is to first sand the areas of bleed through to have a uniformly smooth surface, but not so much as to remove wood (veneer). I then recoat the pieces with epoxy and squeegee it into the pores. You can use old credit cards, plastic lids cut to shape, or even the small rubber edged squeegees the big box store sells. Anything to push it around and into the pores. I then squeegee off any excess epoxy.
Some people thin the epoxy with a small amount of alcohol or acetone. I haven't found it to be necessary, but for a close grained wood like Maple it might help "wet out" the wood.