Slacker

Need help with glue-ups for outdoor furniture

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I’m making a garden bench (Russell Jensen’s Japanese garden bench from Fine Woodworking).

Wood: quartersawn white oak.

Glue: West Systems Epoxy

 

My question is in regards to gluing up 6/4 boards to make the 2 1/2” thick components.

The clamping pressure requirements for epoxy are a little vague. Too much pressure and you squeeze it all out. Too little and there are gaps. 

So far 2 glue ups have gone well, but the 3rd is a bit “gappy”. 

 

I usually use titebond 3 for this sort of thing and haven’t had any issues in the past, but the author calls for epoxy to be used (partly due to him using teak on the original & partly because of epoxy’s superior waterproof qualities)

 

So I’m looking for educated opinions on whether I should stick with epoxy and just figure out what the sweet spot is for clamping...OR switch back to titebond 3 (which I’m more confident with). 

 

In Wisconsin we have massive swings in seasonal temperatures (130 degree range) & lots of rain & humidity in the summer.  Is TB3 equally as good as epoxy in this situation?

 

Thanks for any insights you may share.

 

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West system is a pretty thin epoxy and will penetrate somewhat into the wood especially a porous wood like oak. Up your clamping pressure and rest assured that it'll take a LOT of force to starve the bond. If you want to add some insurance scuff the wood in the center with some low grit paper along the grain. The texture will trap the epoxy.

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This was a bent lamination i did with WS 105 & 207. Each one of those clamps was tightened as hard as i could turn the handle and i didn't have any bonding issues over 5 runs. I don't suggest going to this extreme but it more illustrates that there is less to be concerned about than some will have to believe.

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Chestnut, thank you. This is what I was hoping for. Good to know that I can increase the clamping pressure without having to worry too much. I’ve just read that it’s easy to starve an epoxy joint so I was a little gun-shy when applying the clamps. 

I’m going to rip cut that gappy one and redo it.

Cheers!

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11 minutes ago, Slacker said:

Chestnut, thank you. This is what I was hoping for. Good to know that I can increase the clamping pressure without having to worry too much. I’ve just read that it’s easy to starve an epoxy joint so I was a little gun-shy when applying the clamps. 

I’m going to rip cut that gappy one and redo it.

Cheers!

What's the length and width of the glue area?

If the area is small I'd exercise caution but if your doing a long wide glue joint there is less to worry about. I managed to starve a joint when i glued some Ipe together. It was a 1"x1" area so even a small clamp can do a lot of damage there. That was Ipe a hard dens wood and a small area.

I think the warning is because epoxy is far easier to starve than traditional wood glue.

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They are about 6’ long. I used my quick grip clamps because they kind of have their own limitations in terms of clamping pressure capacity. The first two glue ups I snugged them right tight but the last one (the gappy one) I let off the pressure a bit. I’ll go back to the original amount of clamping pressure and all should be good. Thanks again!3D7AE564-CC43-4BD5-B776-D52D558103BD.thumb.jpeg.78693dc3db9bae277e8086a73d98964e.jpegB1D3C207-B3B5-4506-9F3C-0C72B1A5642C.thumb.jpeg.50b5c32615705e21caaff3bdb6e4049e.jpeg

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Yeah those clamps don't put out much force. When they talk about starving they are referring to the huge clamps that put out 1,000 lbs of clamping force.

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With Quick Grips, it's very difficult to get sufficient clamping force for a glue up on anything but the smallest pieces. You'd probably need 20 or 30 of them to get that glue up done properly.

I have a few & they only get used for holding stuff in place, sorta like a third hand. I love them for that.

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2 hours ago, drzaius said:

With Quick Grips, it's very difficult to get sufficient clamping force for a glue up on anything but the smallest pieces. You'd probably need 20 or 30 of them to get that glue up done properly.

I have a few & they only get used for holding stuff in place, sorta like a third hand. I love them for that.

Yes they definitely have their limitations.

Normally I never use those for clamping glue ups but when I was researching using epoxy as an adhesive, I came across a number of sources that warned against too much clamp pressure/glue starvation so I wanted to be careful. I had a lot of squeeze out using these clamps for the first 2 sets of glue ups so I thought maybe I was squeezing it all out. It was just the 3rd one where I let off the pressure a bit that wasn’t adequate. The first two are very tight, gap free, & solid. 

Thanks for the feedback, now I have a better reference for what I’m working with.

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Nice door! Love that Sapele.

For the garden bench I won’t be applying a film finish at all, just an easily renewable oil finish. Weird how you had so much trouble with the spar varnish.

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Down here in humid Florida oil finishes outdoors will mildew. Should work in your neck of the woods. Western red cedar for outdoor lasts a long time here. Unfinished. P1040970.thumb.JPG.b97cd64443e2c8f4cdaefd981e369cec.JPG

Under all that purple is w.r. cedar. No glass. a garden gate...

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