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Garden Bench glue up ?

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Forum topic by klinkman posted 06-02-2019 10:00 PM 293 views 0 times favorited 10 replies Add to Favorites Watch
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klinkman

42 posts in 297 days


06-02-2019 10:00 PM

Topic tags/keywords: question joining cedar

So I’m looking to complete a garden bench in the next week and have a couple of questions.

It’s constructed from western red cedar and it’s a day or so from glue up, I’m planning on using tite bond III, finishing with a sealer, maybe a stain and then marine varnish. It will get a lot of exposure, little rain (no snow), but it will live outside 365 full time on the front porch.

These are hand cut mortise and tenon joints and of course I want things as square and level as possible. Everything dry-fits nicely, I’ve had the whole thing together once and will go through one more dry assembly final check. But my experience with dry assembly is the pieces don’t seat like they do during glue up, so while it looks okay now, I don’t want to be in for any surprises during gluing (like a leg 3/16” off the ground or something).

Question one: In the past I’ve had a little problem with fiber expansion once the glue hits the wood and moistens it up a bit. What was once a tight joint is now quite stubborn to get together. For reference, on this bench I’ve got a mortise that measures .390 and a tenon that also measures .390 and I’d say that’s a good fitting joint, snug, but you can still press it together by hand. How much play do you generally like in your M&T joints before glue up? Should I sand a few thousands out, should it be more like a “slip in” fit before glue? Does this vary by species or do you just have to experiment?

Question two is what is the right procedure:

1. Glue up the “end sets” first, two sets: front leg, rear leg, side rail. Then after that dries put the front and rear rails and back pieces together to join them all?

2. Glue up the “front and back sets” first, front legs with rail, and rear legs with rail and seat back pieces. Then do the side and middle rails in final frame assembly?

3. It doesn’t matter

4. Glue it all up at once and check square and flatness as you go along, beat uncooperative pieces into place like a dead mule?

My sense is it would be easier to do #1, but I am more concerned about getting a leg lifting from out of square this way.

Any advice is appreciated,
Thanks EC

-- Klinkman, hand tool enthusiast


10 replies so far

View Aj2's profile

Aj2

2321 posts in 2220 days


#1 posted 06-02-2019 11:58 PM

What I’ve found is a different mind set when building outdoor projects. The best design and construction will rely on no glue. Very little exposed joints or areas that will hold water.
Lots of housed mortises pinned or draw board joints.
When I do use glue for outdoors I use gorilla glue. Because it’s fills up space that will keep water out and it’s slightly flexible. Soft wood like Western red cedar do well with it. Glue like epoxy would be too ridged and sometimes darken the grain around every joint it’s used on.
So I think polyurethane is a better choice for outdoor stuff then titebond 3.
But if your project would suffer from the foaming I can see why you would use titebond 3.
Good Luck

-- Aj

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klinkman

42 posts in 297 days


#2 posted 06-03-2019 12:47 AM

Thanks AJ, exactly why I post here, appreciate your input on Gorilla Glue, thats a simple change. Never used on furniture before, do you need to wet the surfaces first? How is the working time?

Any input on the right procedure? Does it matter?

Thanks again

-- Klinkman, hand tool enthusiast

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ibewjon

684 posts in 3215 days


#3 posted 06-03-2019 12:59 AM

Masking tape on the areas where the glue could foam might help.

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SMP

1199 posts in 327 days


#4 posted 06-03-2019 02:56 AM

I also prefer pin or drawbore. And for non-furniture pieces like pergolas, lattice frames etc I will also incorporate metal fasteners into the joints, such as 3” deck screws or timberlocks etc.

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Aj2

2321 posts in 2220 days


#5 posted 06-03-2019 03:38 AM

If you have never worked with gorilla glue be sure to make the time to test it . I usually slightly dampen one side. For instance wet the tenon and glue in the mortise. It will be difficult to close the joint at first so Good clamping strategy still applies.
Good Luck

-- Aj

View Rich's profile

Rich

4575 posts in 1011 days


#6 posted 06-03-2019 04:27 AM


If you have never worked with gorilla glue be sure to make the time to test it . I usually slightly dampen one side. For instance wet the tenon and glue in the mortise. It will be difficult to close the joint at first so Good clamping strategy still applies.
Good Luck

- Aj2

Listen to Aj2. Polyurethane glue requires moisture to cure. Keep a wet sponge and wipe one surface for gluing up.

If I were building it, I’d stick with Titebond III and pin the mortises. Drawboring is really cool and if you like adding that sort of craftsmanship, go for it. But it’d be just as effective to simply glue it up with the Titebond, let it cure and pin it with 1/4” dowels.

-- Knowledge is not skill. Knowledge plus ten thousand times is skill. -- Shinichi Suzuki

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MPython

137 posts in 234 days


#7 posted 06-03-2019 04:36 PM

I built my wife a garden bench 7 or 8 years ago from pressure treated pine. I used gorilla glue and stainless steel screws. It has stood in the weather all this time and is still solid as a rock. Having said that, I will say that I absolutely HATE Gorilla Glue – or any polyurtethane glue for that matter. It is unbelievably messy. But is was the perfect glue for that application. I didn’t put any finish on the bench, so the glue that foamed over and out of the joints didn’t matter, I.E., the glue did’t interfere with the finish because there was no finish to interfere with. In your case, I would be leery of Gorilla glue because you intend to varnish the bench. I haven’t found a way to keep polyurethane glue confined to the joints, so you will very likely have issues with your finish if you use it. Masking the joint before you apply the glue as ibewjon suggested might work. In my opinion the advice to use Titebond III and pin the joints is good advice. If you decide to use polyurethane glue, wear gloves. If you get it on your hands, it’s nearly impossible to wash off. It stains your hands black and has to wear off, which takes several weeks. Wear gloves.

With respect to your plans to finish the bench, if it were me, I would rethink that. If you put a varnish, even a modern varnish with UV blockers, on a bench that lives outside in the weather, it will have to be refinished about every two years. Ask anyone who owns a boat with a lot of mahogany brightwork how long spar varnish lasts in the sun. My father and I built a boat dock from western red cedar. It lived in the sun and water for many years. It was unfinished and weathered to a silver gray color which I found particularly attractive. I would much prefer to look at a silver gray garden bench for years than to face the task of refinishing a beautifully varnished one every two years. YMMV.

I don’t think the order of assembly during the glue-up matters much. Pay attention to how you go about it when you dry-assemble the bench, and use the procedure that is easiest and least cumbersome. If your mortise and tenon joints are good, the bench should go together square. If you’re worried about it, my only suggestion is to glue and clamp it (not too tightly) and let it sit in the spot you intend for it too live. If it settles at all while the glue cures, it should settle so that it sits flat on the floor and cure that way.

My $.02.

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klinkman

42 posts in 297 days


#8 posted 06-03-2019 05:24 PM

Thanks Python, appreciate the input, sounds like I may be over-thinking it (which I’ve been known to do).
Hear you on the maintenance, will ponder the non-finish idea. I’m thinking I’d still use a sealer.

-- Klinkman, hand tool enthusiast

View Aj2's profile

Aj2

2321 posts in 2220 days


#9 posted 06-03-2019 07:46 PM

When I use gorilla glue I wait till the foam has dried and can be touched . Usually the next day then just pop it off with a sharp putty knife. I don’t try to clean up the glue when it’s wet .
If the glue is foaming out so much that it’s dripping all over the ground and making a nasty mess. Your using too much glue. A little goes a long way.
Try not to get on your hands it will stain your skin for at least a week.
Good Luck

-- Aj

View MrRon's profile

MrRon

5572 posts in 3665 days


#10 posted 06-03-2019 09:27 PM

This brings up an interesting question. How tight should the joint be. If the joint is tight (needs hammer blows to fit) then glue may not wet all surfaces as fitting will drive out the glue. If the joint is loose, glue will wet all surfaces, but will the joint strength suffer (not enough wood-to-wood contact)?

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