The subject says it all. Foam? No way. We're using western red cedar clears, for high-end, no corner-cutting patio furniture. And a subset of our production is special orders made from Ipe or Jatoba. Anyone know the best for this? I'm looking at West Systems and WeldwoodŽ Marine Resorcinol Glue. Am I nuts? No experience with either.
We need something that can be used for mitre cut joints, side grain or face grain laminations, and other general uses. 50% of our units are stained with Cabot's Australian Timber Oil [oil based]. Shouldn't matter but thought I'd mention it because we have to avoid shiny, slick spots when you leave residual glue. 2-part is ok but obviously 1-part makes it easier for the workers. [I don't believe Titebond III is worthwhile even though mounting evidence says it is. Just not sold on it. I'm comfortable with a more commercial product].
From contributor De
West System has a long history of success with WRC. Thousands of cold molded boat hulls have been built using it.
From contributor Da
I would give a stronger consideration to resorcinol over epoxy. While I am sure the boat hulls are a good testament, I have had epoxy 'failure' related to starved joints. Resorcinol has its drawbacks (temperature, toxicity), but is what is holding all that A/C Fir plywood together.
Being woodworkers, tightening clamps is fundamental and we have had countertops and other joints open since we literally squeeze the epoxy out of the joint. Epoxy likes a thick glue line, and this rules it out for appearance in some things.
I understand a recent Fine Woodworking article suggests epoxy as a good mortise and tenon/exterior door glue, but if your joints are proper, there will be little room for a thick glue line.
From contributor pa
So you are saying epoxy is less viscous than resorcinol types? The woodshop is in Tijuana, Mexico so the temp is low 60's to mid 70's, and low humidity. The shop has no heating.
From contributor pa
Also - boat hulls are not the same joints as furniture. However, I suppose letting epoxy dry a bit before clamping would help to make more viscous.
What toxicity measures have to be taken with resourcinol? Expensive breathing systems? They only have elasticized masks for general woodworking dust, etc.
From contributor Da
Go to Weldwood tech for MSDS and exposure recommendations on Resorcinol. Urea and a few other demons. You can also try the link below. It needs heat and wood of the same temp to set correctly. It likes 80F degrees or better.
Epoxy can be made more viscous with thickeners. This will not prevent starved joints, as I understand it. The pressure of 'normal' clamping squeezes the epoxy to a very thin glue line. This is what is needed for most glues, but not epoxy.
From contributor pa
I can't artificially or any other way raise the wood temp to 80 degrees, or any degrees. Or can I, without reinventing the wheel?
I actually tested "Bolder Bond" . The relatively new poly glue that foams ~ 40% less than the other poly's. Trouble is certain joints are hard to clean out the foam. Tight spaces. And trying to remove foam, the workers will damage the soft cedar. Then sanding is rq'd. Chasing the tail. A lot of extra work. But beyond this problem B Bond does work. There must be an overall better solution...? Maybe using B Bold on less difficult joints, together with the epoxy on the difficult ones. This would highly minimize the use of epoxy. Just thinking.
From contributor B.
I've done my own tests on Western red cedar and found that the polyurethane glues work well. The downside is your joints need to be tight as there is no gap filling strength in the glue. In face in a Fine Woodworking test several years ago the polyurethane glues scored the lowest for joint strength.
I too tested out Titebond 3 and found it to work on WR cedar. However like you I've not made the change.......just not convinced.
We will sometimes use West Systems but the heavy glue line makes for issues if it's not a paint grade project.
So the bottom line for us is to make sure we have good joint/seam work and to use polyurethane. I like the Franklin (Titebond manufacturer) brand.
BH Davis
From contributor pa
Well, I decided on TB III. Cleaning up foam is too time-consuming and sometimes removing it will ruin the softwood with who knows what tools. Then sanding over again - chasing your tail. I don't want the labor hating my project. I'm also betting that Franklin would not lie. Especially when you tel 'em it's for production. Do do so would be a very, very high liability for them.
From contributor Ge
Nothing wrong with TB III, but for the longest outside durability, uv stabilized epoxy with a thick joint (as David as stated well) or resorcinol would provide longer life indeed. The key is that these adhesive have a chemical reaction that will not allow the adhesive to soften with heat or moisture or uv or insects or fungi.
From contributor ar
Epoxy thickeners do two things. They thicken the glue to keep it from running out of the joint and they also hold the glue by absorption keeping it all from soaking into the wood. Laminating epoxy cures slowly which gives the wood a lot of time to soak it up. Thickener helps counter that action and keep more glue in the joint.
