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Flattening a warped live edge?

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Forum topic by aamk posted 10-12-2018 02:32 AM 346 views 0 times favorited 13 replies Add to Favorites Watch
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aamk

6 posts in 329 days


10-12-2018 02:32 AM

I milled some pecan for a live edge table and I had someone build it. The table turned out beautiful however after about a week it bowed/cupped up. I had him use Rubio monocoat as the finish so im guessing the monocoat or air flow in general wicked the moisture away faster from the top than it did the bottom. The bottom in unfinished. I cant really seem to find any good solid answer on the best approach to flattening people say plane it but I would have nothing but sawdust left. I keep thinking that eventually its got to reach equilibrium and go back to a flat state but I seem to be reading that that will not happen.

I read maybe I can put it in grass over night with concave part down and let it reabsorb moisture or even iron it? If I can get it flat I will apply coating to bottom side definitely. I was even thinking about bolting it down to the table base with 4 bolts aross the top and then slowly working each one tighter and tighter a little at a time until it bends flat if that would work?

I would appreciate any constructive help/feedback.


13 replies so far

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Steve

627 posts in 724 days


#1 posted 10-12-2018 03:15 AM

what was the moisture content on the piece after you milled it?

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Aj2

1713 posts in 1940 days


#2 posted 10-12-2018 03:40 AM

According to the experts finishing both sides is not necessary to prevent cupping. There’s lots of reasons why wood will change its shape when it’s brought in doors.
The only way I know to take a cup out of a board is rip it in half flatin one face then send it through the planer. We do this as many times as needed and sneak up to its final thickness.
Trying to force the wood flat is futile.

-- Aj

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lumbering_on

316 posts in 632 days


#3 posted 10-12-2018 03:56 AM

The cupping upwards actually means the bottom has a higher moisture content than the bottom, which causes the wood to curl towards the dry side as it is more taut.

I’m not sure if you can flatten it out for good, but your best bet would be to remove the table top, and see if you can dry the bottom out by laying it on it top for a while, and try putting a bit of weight on it using stickers. It’s worth a try, but the reality is that it sounds like the MC was too high when the table was put together.

You could also try using this dehumidifier kiln :https://www.youtube.com/watch?v=LF8vCwsHp1g

I have seen smaller boards, particularly flooring flatten out, but these are far from the live edge you would have used.

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aamk

6 posts in 329 days


#4 posted 10-12-2018 08:49 AM

I found this video https://m.youtube.com/watch?v=wEy4zJ0cizM there seems to be hope and he gave a great explanation of what happened. Sounds like oil finish on one side and not the other was the culprit. I’m going to wet the cupped finished side turn it upside down heat the table put an air mover across the unfinished side see if I get any progress and then finish the bottom. The table was beautiful hopefully I can get it flat again.

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lumbering_on

316 posts in 632 days


#5 posted 10-12-2018 12:16 PM



I found this video https://m.youtube.com/watch?v=wEy4zJ0cizM there seems to be hope and he gave a great explanation of what happened. Sounds like oil finish on one side and not the other was the culprit. I’m going to wet the cupped finished side turn it upside down heat the table put an air mover across the unfinished side see if I get any progress and then finish the bottom. The table was beautiful hopefully I can get it flat again.

...

- aamk

It’s just Charles Neil – what does he know? ;)

Yes this is sarcasm – before anyone takes this the wrong way.

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Aj2

1713 posts in 1940 days


#6 posted 10-12-2018 01:38 PM

What the neck are those four patches of wood going across the grain. Something looks fishy ~>

-- Aj

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HokieKen

6246 posts in 1280 days


#7 posted 10-12-2018 03:18 PM



What the neck are those four patches of wood going across the grain. Something looks fishy ~>

- Aj2

I’m guessing they were used to aid in alignment when the top was glued up. Maybe? I was wondering the same thing.

-- Kenny, SW VA, Go Hokies!!!

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Steve

627 posts in 724 days


#8 posted 10-12-2018 03:21 PM

Why isn’t the person who built the table fixing it?

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aamk

6 posts in 329 days


#9 posted 10-12-2018 08:11 PM

He thought those would keep it from bowing I didn’t think it would work I expected the metal would but it pulled the bolts out anyway. He offered to try but I will see. How far I can get with it.

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lumbering_on

316 posts in 632 days


#10 posted 10-12-2018 08:32 PM



He thought those would keep it from bowing I didn’t think it would work I expected the metal would but it pulled the bolts out anyway. He offered to try but I will see. How far I can get with it.

- aamk

I’ve seen maple rip out 3” #10 screws, so it’s not surprising the bolts didn’t help.

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JayT

5862 posts in 2353 days


#11 posted 10-12-2018 10:08 PM

If you paid someone to do that table top, get your money back and don’t ever have them build anything for you again. No one that understands wood movement would ever have done those recessed cross grain pieces. Even if the table didn’t cup, it would have split in short order due to seasonal changes. What a waste of a couple nice pieces of bookmatched pecan.

There’s lots more to being a good woodworker than the ability to glue and screw pieces of lumber together.

-- In matters of style, swim with the current; in matters of principle, stand like a rock. Thomas Jefferson

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aamk

6 posts in 329 days


#12 posted 10-12-2018 11:24 PM

There was a lot more than just the top he built the base got everything squared I knew it was his first live edge attempt and he planned the wood with the router and sled. I will mil some more this winter and try to find a kiln and go that route. I paid 400 for the building of the entire table so it was far from getting ripped off and I really don’t think the boards on the bottom caused it I believe it was from only finishing the top.

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Shamb3

33 posts in 323 days


#13 posted 10-13-2018 03:41 AM


There was a lot more than just the top he built the base got everything squared I knew it was his first live edge attempt and he planned the wood with the router and sled. I will mil some more this winter and try to find a kiln and go that route. I paid 400 for the building of the entire table so it was far from getting ripped off and I really don’t think the boards on the bottom caused it I believe it was from only finishing the top.

- aamk

In the video you posted, he said just sanding one side of a piece of plywood could lead to warping. Imagine what routing not kiln dried lumber could do.

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