WOOD MOVEMENT QUESTION

[MichaelW2014]

Does wood move at all over time if it is very well sealed with an acrylic lacquer?

 

[Holmz]

A latex balloon looks pretty sad after a day or two, and a mylar one lasts a week.
The latex has a more porous surface so the helium gets out faster.

Humidity is not exactly the same, but how well the wood is sealed determines how long it takes it to loose or gain water.

An epoxy might be better than a lacquer... Or maybe not.

 

[Scott B.]

Does wood move at all over time if it is very well sealed with an acrylic lacquer?

Yes.

 

[MichaelW2014]

thanks. what you wrote makes sense holmz

 

[MichaelW2014]

wax, oil, laquer, etc, which seals the wood best without ruining the feel and look of the wood?

so if you seal it with 2 coats of wax is that at all good enough and will lead to minimal shrinkage/expansion? or is wax the worst in this regard?

is there a set of guidelines for wood type and finish type in relation to wood movement? a guidebook perhaps?

 

[tiralie]

wax, oil, laquer, etc, which seals the wood best without ruining the feel and look of the wood?

Improperly applied all will ruin the look and feel of wood. They all seal the wood against damage/usage to various degrees. Some say it slows the expansion/contraction but that varies between species and relative humidity or changes in relative humidity.

so if you seal it with 2 coats of wax is that at all good enough and will lead to minimal shrinkage/expansion? or is wax the worst in this regard?

Wax is a good coating depending on usage, but doesn't prevent shrinkage/expansion.

is there a set of guidelines for wood type and finish type in relation to wood movement? a guidebook perhaps?[/b]

I would suggest Understanding-Wood by Bruce Hoadley
Here is a shrinkage/expansion calculator
There is a lot of good information Indoor Wood Shrinkage and Expansion on Woodweb.com
Tim

 

[teocaf]

I would add a few more resources to what Tim just added:

another wood movement calculator:
http://www.woodworkerssource.com/movement.php

Lee Valley also sells a nifty wheel type calculator which is what I use:
http://www.leevalley.com/US/wood/page.aspx?p=46281&cat=1,46096,46109

When it comes to wood movement in relation to finishes, I tend to refer to Bob Flexner's excellent reference:  Understanding Wood Finishing book.  Incidentally, when he discusses how to choose a finish, on page 190, he states as his number 1 point:  "Eliminate wax as a choice".  He gives his reasons, but I can't quote large portions of the book.  Get the book or see if it's being published as an ebook and I think that's a very good start on this very broad topic.

 

[MichaelW2014]

these responses are excellent, my thanks to both of you guys for this.

 

[bertv]

The only way to avoid woodmovement is to change the properties of wood itself. There are techniques to do this (eg high pressure boiling), but these are not in the realm of simple woodworkers like us.

Best practice is to study wood and learn from the mistakes and successes of others.

OT: keeping your brench dry will go a long way towards keeping it in good shape. Using a coating that breathes' will prevent cracking of seams and ingress of moisture. Products like hard oil or epoxy require constant care and updating.

 

[MichaelW2014]

The only way to avoid woodmovement is to change the properties of wood itself. There are techniques to do this (eg high pressure boiling), but these are not in the realm of simple woodworkers like us.

Best practice is to study wood and learn from the mistakes and successes of others.

OT: keeping your brench dry will go a long way towards keeping it in good shape. Using a coating that ‘breathes' will prevent cracking of seams and ingress of moisture. Products like hard oil or epoxy require constant care and updating.

thanks for the tips. i will consider them.

 

[Scott B.]

I think the only way to avoid wood movement is to not use wood. But what fun would that be?

Expansion and contraction is just how wood breathes. Even after being harvested, milled, cut, nailed to the wall, sanded and finished, it is still breathing and moving.

Finish either assists with dimensional stability during movement or throws it out of balance.

 

[tiralie]

Lee Valley also sells a nifty wheel type calculator which is what I use:
http://www.leevalley.com/US/wood/page.aspx?p=46281&cat=1,46096,46109

Thanks, I didn't realize they sold this. Good little tool.

When it comes to wood movement in relation to finishes, I tend to refer to Bob Flexner's excellent reference:  Understanding Wood Finishing book.  Incidentally, when he discusses how to choose a finish, on page 190, he states as his number 1 point:  "Eliminate wax as a choice".

In context, Flexner is against Wax as the only finish unless it is a decorative objects that won't be handled much. Wax does not offer any protection against water and is difficult to repair if a watermarked. He is however Ok with wax applied over other finishes.

Get the book or see if it's being published as an ebook and I think that's a very good start on this very broad topic.

You can get a copy of Understanding Wood Finishes PDF which is the first version (I think) and does not contain the same info as the updated version [member=2205]teocaf[/member] refers to, but it's still a good read and contains different information than the eponymous "Flexner on Finishing" book.
Tim

 

[mouppe]

You can veneer on plywood or MDF if you wanted the look of wood and almost no movement.

 

[MichaelW2014]

thanks scott, tim, rl, for all the info. i will refer back to this thread from time to time as needed. good bunch of info here.

 

[monstrol]

My Sicilian ebeniste(french) friend always tells me "the wood...it never dies"...