Glue for high heat (wood) applications

[Ryan Mooney]

A buddy of mine has a pub/pizza joint and the pizza peals they bought from some online place.

The upshot is that the original glue joints are failing with a fairly high degree of regularity due to the high heat environment. I've fixed a handful of them using titebond III without them failing yet.. but was wondering if there was a better glue to use in this sort of environment? I see some high heat epoxies but was concerned that they would be to brittle as presumably the wood is going to be moving a fair bit (dried out by a days use in the oven then "re-hydrating itself" over night).

[John K Jordan]

Don't know about the glue but how about making some new ones from a wood that doesn't move much, like mesquite?

[Ryan Mooney]

Don't know about the glue but how about making some new ones from a wood that doesn't move much, like mesquite?

They like the light ones which kind of limits the wood choices a bit. Something about heaving 20" pizzas in and out of an oven for 8 hours makes you appreciate that feature more I suppose.

They currently have mostly ones made from some sort of "white" wood, I think alder or similar would be a reasonable substitute and one from oak. No one would use the oak one until I took and knocked a bit over half the thickness off of it and its still a lot heavier (and now thinner) than the others.

[Wayne Lomman]

Are the pizzas actually cooked on these? Cheers

[Jamie Buxton]

PVA (Titibond et al) is known to be thermoplastic -- that is, it gets flexible when it gets hot. I'd try epoxy. Epoxy is also quite water resistant, in case these tools get washed occasionally.

[Jay Jolliffe]

Don't know if epoxy would work as I use a heat gun & scraper to take excess epoxy off after a glue up...

[Jamie Buxton]

Here's an epoxy with a service temperature range of -60F to 450F -- http://www.masterbond.com/tds/ep42ht-2

[Ryan Mooney]

My understanding on PVA glues was that the old "white" PVA glues were more thermoplastic (and I think that may be what the original glue was .. but don't know) and that the newer cross linking ones were "better" (for some value of "better"). My tentative hypothesis (with no backing facts) is that TB III might be better than II because more water resistant probably means more cross linking.


Here's an epoxy with a service temperature range of -60F to 450F -- http://www.masterbond.com/tds/ep42ht-2

Yeah I was looking at some of those, that one is at least room temperature curable which is nice some of the other ones I found wanted to be baked at high temperatures (and with them being ~4' long that looked challenging). I have zero experience with that sort of epoxy though so was hoping perhaps someone else had before I dropped the dollars on an experiment.


Are the pizzas actually cooked on these? Cheers

No heh, that would be a new level of difficult. They just use them for shuffling the pizzas in and out of the (very hot) oven. They also tend to get stored next to the oven so they're pretty warm all day.

I believe the oven is kept a bit above 500F but the actual peals don't see temperatures in that range for any extended length of time. The temperature where they are stored is somewhere a bit north of 100F most of the time.

[Bradley Gray]

I would be hunting down some 20" boards.

[Wayne Lomman]

Most epoxy will withstand continuous temps of 85C with intermittent peaks to 120C. Cheers

[Ryan Mooney]

Wayne, that's interesting. Epoxy is looking more and more attractive.


I would be hunting down some 20" boards.

That's certainly an option that may eventually float to the surface.

[John TenEyck]

Hi temp epoxy or resorcinol glue.

John

[Ryan Mooney]

resorcinol glue.

Now there's a tempting thought.

I wonder how much better a phenol-resorcinol like Aerodux would be than say Dap Weldwood (and if it would matter). I used Aerodux long ago on some water skis, the main downside would be the rather extremely visible glue lines (deep purple). Dap just might be what the doctor ordered.

[John TenEyck]

Weldwood PRG would probably be fine, too. Any thermoset resin is likely to work. I tried looking up the max. temp limit of it, but couldn't readily find it. I'm sure could with a little digging though.

John

[Ryan Mooney]

Yeah I see that the usage guide has curing temperature up to 140F for Weldwood PRG so I'm going to say its definitely higher than what I've been using.

Thanks for all the ideas everyone!

[jack duren]

We use Gorilla glue for heating tops..

[John Blazy]

The ultimate, cheap high temp glue is common silicone. Pretty elastic in a joint, but I have used it as a high temp adhesive, and have had zero breakdowns in bond strength. I use it in molds for forming stuff in my big laminating ovens which are always near 300F for hours at a time.

[Myk Rian]

If what you're using works, why change?

[Glenn de Souza]

If what you're using works, why change?

I had the same thought. Since the ones you've repaired have not failed, how do you know you haven't already solved the problem?

It would be interesting to know what type of glue failed originally.

I made two pizza peels years ago and glued them up with TBII. No signs of failure, but then again, they're being used in the home, and very occasionally at that so I'm sure the ones you've repaired were subjected to much more wear and tear. Out of curiosity, were any of them ever run through a dishwasher?

[Ryan Mooney]

No dishwasher on these - they won't fit :) I wish I could say the same about the cheese boards I made :mad: Although I did expect that :rolleyes:

I can't say with 100% certainty that none of my glue joints have failed as there are something like ~9 glue joints per peal and I've fixed each one a couple of times (and failed to mark which were repaired on the first round being under the apparently mistaken theory that it was just a couple of bad initial glue joints).

I don't believe silicon will have sufficient strength in this application.

Someone else pointed out this which was a) surprising and b) points out the obvious that I need to do a couple of test runs :D
http://www.frets.com/FretsPages/Luthier/Data/Materials/GlueTest/gluetest.html

[Glenn de Souza]

It might be worth a call to the people at Roo Glue. I say this because their website talks about an industrial division. It may be that one of their industrial or non-industrial products might be suitable for your application. Just a thought