Cupped table top

[ScottGoddard]

Hi - I have been making a small round table and i came to start fitting the top to the leg and it cupped...Any ideas of how to fix this?

The wood was about 8% moisture when i start and is ranges between 2% - 6%. I let the wood move after milling it for a week, then glued it up (alternating the wood) and let it sit for another few days. Made the required cuts, shaped and sanded and now its cupped...

Not sure you and see it from the pictures but cupped about 4-5 mm

 

[MikeG.]

Are you having a traditional sub-structure of aprons? If so, would fixing the top to this apron be enough to pull it flat, in your opinion? If so, that would be my preference.............just making sure my buttons were tough enough to manage the extra strain.

 

[ScottGoddard]

Hi, yes, going to put inserts into the table top and bolt in down (bolts will be in elongated holes). Although not sure in will be strong enough to pull it down ?

Picture below of thee legs

 

[Sgian Dubh]

The wood was about 8% moisture when i start and is ranges between 2% - 6%.

I'm guessing you mean between about 12% and 6%?

..Any ideas of how to fix this … cupped about 4-5 mm?

What Mike has suggested may be all that's needed.
However, how was the panel stored between the making and coming back to it to find it cupped? Was it laid flat on a bench, or did you have stickers underneath so that air could circulate freely all round? What I'm getting at is that if air can't circulate freely all round it can cause one face to change moisture content whilst the other face is relatively protected and doesn't change so much, leading to cupping. Sometimes, even if the piece is stored so that air can circulate freely it will still cup, which is likely to be something like stress working its way out.

Anyway, you might try using a plant sprayer or damp rag on the concave side to see if that straightens the cupping before you fix it down. Just a light application of water, not a soaking, enough that will dry out in about 20 to 30 minutes at room temperature. It may work only temporarily, or it may be a permanent fix, but probably worth a cautious try.

Overall though, with only a 4- 5 mm cupping across the width, fixing the piece down firmly to the framing (allowing for cross grain movement) will probably be enough to hold it flat. Slainte.

 

[ScottGoddard]

The gage read 2% at the end grain...

I did store it on cookies as i was sanding it and probably left it there over night. I also brought the top indoor to show the misses and left it over night. Maybe this caused it as it dired more and wasnt secured down.

Not sure the fixing will straighten it out as they are set in and therefore will pull down at the edges of the table.

Will have to try the water trick.

 

[MikeG.]

The gage read 2% at the end grain....

Time to chuck your gauge out and get a new one!