Brainstorm - Edge jointing with TS55/75?

[tbellemare]

Even metal relieves when it's milled.  

Tom

 

[Michael Kellough]

On of my board is not flat any more.  Yesterday afternoon it was flat flat flat on one face after jointing.  The other face was curved, fat in the middle.  I didn't plane it parallel.  Today it's fat in the middle and curved on both faces.  I suppose I can plane that out.  But it struck me as funny.  Wood is a funny thing.  This wood is steamed European Beech and that stuff is funnier than most.  I wonder if this would have happened had I planed the other face parallel?  This kind of reminds me of veneering.

Generally, you have to take wood off both sides of a board to keep it balanced.
If the board is thoroughly seasoned and has no internal tension (you never know
until you cut it), you might get away with milling only one side, but usually
if you joint one face you should go ahead and plane the opposite asap.

 

[peter halle]

By example, I had a job back in January where as part of the project I had to make a blank cover plate to cover an abandoned telephone receptacle box in a wall.  The wall was covered with maple plywood as part of the project and the plate had to be maple too.  I ran the stock thru the planer to get it down to the thickness I needed, routed the edges and was thrilled - until the next morning.  The milled side (top) was no longer flat.  My remedy - put it on the dashboard of the truck and let it sit for 4 hours.  Equilibrium was achieved and it was installed. Still flat to this day.

Along with the release of internal stress I suspect that the movement was allowed by the opening up of the cells of the wood and the subsequent accelerated additional drying on that side.  Learned my lesson - plane both sides.

Peter

 

[ForumMFG]

Thats a pretty cool and easy fix wouldn't you say?

 

[peter halle]

I think that I got lucky.  But it does work in other situations.  Have you ever walked across a newly installed hardwood (unfinished) floor and find it to be perfect?  Come back a few days later and the outside edges of the boards have cupped upwards?  Leave it alone and it will achieve equilibrium - the topside is drying out faster and the bottom is moister.  Sand it too soon and when it achieves equilibrium the center will be humped because the movement has reversed and now the edges that were sanded to make the floor flat are now thinner.

You'll also see this with pressure treated decks - particularly if the deck is close to the ground.  The bottom will almost always moister and when the top dries the outside edges cup upward.

At least this is what I've experienced.

Peter