I have a project and need some advice. I have a medium size sign I need to build for a local church. The design plans call for 6x6 posts and an arched top. Doing the bending of the facia boards on the top is not a problem. But I plan on making the 6x6, and the facia, from a glued up lamination. The wood of choice is mahogany. Now for the question, "What is the absolute best glue to use?" Bear in mind this is going to be outside in the wonderful humid and hot Alabama weather.
Sounds similar to problems related to boatbuilding. There, the choice #1 is epoxy, #2 polyurethane. Both messy, epoxy can induce alergy-wear latex gloves. Good luck
Sounds similar to problems related to boatbuilding. There, the choice #1 is epoxy, #2 polyurethane. Both messy, epoxy can induce alergy-wear latex gloves. Good luck
Yes, they would be good choices. I've used epoxy outside and I've used Titebond III with excellent results so far, but it has only been a year. Titebond II I've had outside for about 5 years now with no problem. I've yet to try a urethane yet though.
| I have a project and need some advice. I have a medium size sign I | need to build for a local church. The design plans call for 6x6 | posts and an arched top. Doing the bending of the facia boards on | the top is not a problem. But I plan on making the 6x6, and the | facia, from a glued up lamination. The wood of choice is mahogany. | Now for the question, "What is the absolute best glue to use?" | Bear in mind this is going to be outside in the wonderful humid and | hot Alabama weather.
My experience is limited; but I've had good results in Iowa with both Epoxy and TBIII. I'm fairly confident that the epoxy will hold up - but I'll have to let you know about the TB in another 20 years or so...
I agree with others, Epoxy or Gorilla. That being said, I think most glues will work if there is good preparation and the finish is done well and maintained. I made a sign 10"x26" from old fir scraps, glued with good old TB2. The sign is used in the local mountains. The sign is painted and has lasted over 10 years!
Dave
Posted Via Usenet.com Premium Usenet Newsgroup Services
You should. I used to use Gorilla, now I use Elmer's polyurethane glue. Good stuff. In another reply in this thread someone said that polyuethane doesn't fill gaps. Not sure where that came from. The polyurethane foams up and most certainly will fill gaps. I know that there are different formulations, some billed as low foaming, but unless the gaps are ridiculously large it will fill them.
This begs some questions. I've used both and never had either one fail, whether indoors or out. What exactly failed, and how?
Frankly, any. The epoxy is so much stronger than the wood it doesn't matter. If you're looking for a brand recommendation, West Systems Epoxy by the Gougeon Bros. is the gold standard. They literally wrote the book on epoxy starting with their work on ice boats. They have a very extensive web site with a tremendous amount of information.
formatting link
can get West System products at West Marine in your area:
formatting link
poster mentioned microballons which is a marine industry staple. The microballoons, West's Microlight, is a fairing filler and not the best product for bonding. Their Colloidal Silica (think sand in suspension) or their High Density Filler would be preferable, , but frankly, you can use just about anything as a thickening agent. Sand would work if you mixed it in well. Don't do that, though, as it gives me the shudders to think about it!
R
Yah, the foam fills the space, but it doesn't provide strength. "Gap filling" is a glue-boffin term for "fills the gaps and supplies strength." The microballoon fans here can give you the details.
I do take your point about needing to clarify that the properties of a gap filling polyurethane doesn't equate with the full strength of a tight fitting joint with the same glue, much less epoxy, but the polyurethane will certainly add more strength to a slightly loose joint due to its foaming properties. Saying it doesn't provide strength is as much of an oversimplification as the original comment that it doesn't fill gaps.
I'm fairly fluent in epoxy, been working with it for twenty-five years knocking around in boat yards, etc. Microballoons are the lowest strength filler, but provide all the strength you'd need for woodworking and cabinetry work.
You can use waterproof woodworker's glue. Make sure it says "waterproof" or "water resistant" on the package. Elmers or Titebond are two good brands. Use stainless steel fasteners to prevent staining. My concern would be protecting the mahogany from the elements--maybe a marine epoxy varnish.
Since everybody else has recommended PolyUrethane and Epoxy I will give you a third alternative: Resorcinol. Resorcinol has a red glue-line, but that will not show with your Mahogany. This is the stuff typically used here in NZ to manufacture laminated beams etc - it's boiling-water proof...
I made some outside stairs to our verandah by laminating 6x2 into 12x2 with Resorcinol near 10 years ago and they're as good as the day I made them. Untreated, non-painted eucalypt.
Yes, Resorcinol! I had forgotten - not used it for years. Used to be the glue of choice for exterior joinery. Simpler to make up than epoxy - what is it, powder into liquid or the other way around? I forget.
Seems like it could be a bit harder to find though, right? I mean I don't recall seeing it at HD.
And, uh, not to ruffle feathers, but also not gap filling. Joints should be well fit. I suppose you could say it would add strength across a gap,(like polyurethane, too) but only like caramelized sugar adds strength to flan.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.