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cupping question


gator

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Don't let it sit!

Two tricks that will help. First plane equal amounts on each side. Flip the wood over after each pass. This keeps the moisture level equal on both sides.

Second, don't set the boards flat on a serface or floor. If you are planning several boards, stack with stickers or wood spacers in between each board. This allows moisture to circulate equally around the boards. If your planing just one or two boards, lean them against a wall or your work bench to allow for air circulation around the entire board.

This should help with cupping

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It's all moisture as above ,stated ,look at the end grain will give you the indication of which way the curves are are going to be the natural way it will cup,even flat wood will cup if moisture is present on on side or the other from air vents etc when complete helps to seal both side and ends .If you want to see dramatic effect bring hoe a new sheet of 1/2 plywood and lay in your front yard in the sun for a couple hours and you are likely to have a potatoe chip 4x8' 

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okay guys and gals .planed some dry wood 3/4  to 1/2" and left sittin over night. cupped real bad. any tricks to stop this are fix it after the fact?

Hi Gator, Dan's information is correct. Stand the board on end. One of the reasons for it cupping is, when you lay it on a flat surface air can't circulate under the timber, hence it cups. That's why the timber you see in the lumber yard is stickered, so that air can circulate all around the timber. One other reason is the board may have been flat sawn, if it had been quarter sawn it would not cup. It could also have been badly kilned. Hope this helps Gator as I do not profess to be a technical writer, just what I remember from my apprentice days at college, hundreds of years ago. ;)  ;)  ;) .

Rob Roy.

Edited by Rob Roy
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I usually plain my wood when the moisture  of the wood is around 6 to 8 % then stack it flat in my wood shed over the klast 3 years i have only had one 1/4 thick board warp. you can use a moisture Gage or there is a website . just Google  ( lumber weight calculator

ike)

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Best trick is to take a heat gun and heat the cupped side and watch the board flatten out as you do this.

 

A little bit of my  brilliance come into play here, once more..........Which is considered the 'cupped side' ?  With the board laying with on a surface does it sit like a rocking chair rocker or it the two sides laying against the flat surface with the hump side up ?

 

Dick

heppnerguy

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A little bit of my  brilliance come into play here, once more..........Which is considered the 'cupped side' ?  With the board laying with on a surface does it sit like a rocking chair rocker or it the two sides laying against the flat surface with the hump side up ?

 

Dick

heppnerguy

You heat the concave side,,, lay it down so it rocks...  start in the center and work toward the outside back and forth

LOL  If it gets worst, turn it over  :razz:

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Thank you I will have to give this a try. Funny thing is, about an hour ago I went to my wood supply to pick a piece of wood to cut my next project and low and behold, The one that caught my eye was cupped and I immediately thought about this post. Because I had not yet seen your reply,Larry, I reflected on my question. Now I can go and give the idea a try. I will let you know, if I am successful.

 

Dick

heppnerguy

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Thanks for a great thread.  Lots of good info here.  I was looking at some thin wood at the HD yesterday, and it was all pretty "cupped".  I passed on it and some of the popular was really pretty stuff.  I may have to rethink a couple of the prettier pieces.  Is there a chance it would crack from using a heat gun?  Like drying it to quickly with the heat?

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Thanks for a great thread.  Lots of good info here.  I was looking at some thin wood at the HD yesterday, and it was all pretty "cupped".  I passed on it and some of the popular was really pretty stuff.  I may have to rethink a couple of the prettier pieces.  Is there a chance it would crack from using a heat gun?  Like drying it to quickly with the heat?

 Of course!!!!!!you can dry it too quick. You don't want to burn it (maybe late)

Slow is good ...practice

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 Hello Dick, what's the verdict? I gotta go to bed soon. ;)

Thank you I will have to give this a try. Funny thing is, about an hour ago I went to my wood supply to pick a piece of wood to cut my next project and low and behold, The one that caught my eye was cupped and I immediately thought about this post. Because I had not yet seen your reply,Larry, I reflected on my question. Now I can go and give the idea a try. I will let you know, if I am successful.

 

Dick

heppnerguy

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