# How to clamp a finished surface without damage?



## RobH2 (May 11, 2008)

I've been making crokinole boards and I've ruined some finished decks by my clamping procedure and need some advice.

I finish the deck and rub it out after it cures, then I clamp it down to the finished base. Last time I put a towel over the deck and piled sand bags over that to weigh it down. The sand evened out the weight but I had an imprint of the towel fibres left in the finish. I'm wondering how to avoid this?

Things I'm thinking of trying next…

Should I put the sand bags directly on the surface?
Should I use a smoother textured cloth?
A finished piece of wood the same size of what I'm gluing?

Is one of these options better than the other? Or is there something else I am overlooking?

For finish I was using polyacrylic. Now I am using lacquer. Perhaps that alone will make a difference but I don't want to take any chances. I am waiting 10 days before rubbing out by the way.

Thanks in advance.
-Rob


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## KYSean (Jul 21, 2008)

Why are you not attaching the board to the base before you put the finish on it?


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## RobH2 (May 11, 2008)

After I rub out the deck I then drill the centre hole which gets plugged from underneath to the appropriate depth. It's just the order that I need to do things. If I drill the hole first then it gets filled with water or oil when I rub out, which raises the grain and causes issues.


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## KYSean (Jul 21, 2008)

Pictures are worth a thousand words.


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## JBrow (Nov 18, 2015)

Rob,

Your description of the project leaves me confused - but then I am easily confused. Nonetheless, if an imprint is imparted to a finished surface, it sounds like the finish is soft when weight is applied. I would think a fully cured finish would be impervious to imprinting, regardless of the finish used. I do not know the full curing time for either lacquer or polyacrylic. But I doubt the cure times published on the can anticipate applying weight to the finished surface. I would guess the cure time would be longer when applying weight to the finish. Even if a smooth surface were used as a clamping caul on a soft finish, problems could arise. I would fear the surface would stick to a soft finish and when the caul is removed, it could lift some finish.


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## DrTebi (Jun 16, 2009)

I just glued up a project that I applied finish on before. I used leather on my clamps. I cut out little pieces of leather and stick them with double-stick tape to the clamps ends.

My finish was shellac. It did not leave any marks, even though it was clamped fairly hard.

Here are some suggestions:

Do as jBrow suggested, let the finish cure longer
Use a different finish. Try shellac for example (which I personally find to turn out much nicer than poly) Shellac also cures very quickly. I had it less than one day curing before clamping.
If whatever technique leaves marks, try wet-sanding with a very high grid. I use 1500, it leaves a smooth, almost glass-like finish. Sort of like a semi-gloss finish, and feels great.
Try leather as opposed to a towel etc. Maybe your original technique works, just use a smooth leather piece in the size of the circle instead of the cloth.

Good luck.


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## Aidan1211 (Feb 20, 2016)

Make up some pieces of wood and use spray adhesive to apply a soft leather veneer over the pieces so you can use them as clamping culls. That has worked for me in the past to keep from damaging stuff that was delicate. If you have a face that isn't flat and you are doing a bunch of sets then I would make a profile that somewhat matches what I was clamping and do the same and veneer some soft leather on the newly shaped culls. Best part is they will last a lifetime and you can reuse them.


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