Warping

[Dave K.]

Question for y'alls...

I've adopted the routine of painting the interior of my walls with flat black paint...just in case lighting gets added down the pike. But does having both sides painted (as well as braced, of course) also help prevent warping over the long haul? T'anks.

[deemery]

Short answer, Yes. 


(Longer answer, warping happens because moisture gets into the wood.  The paint seals the wood, making it much harder for moisture to intrude.)


dave

[Dave K.]

Not only do we have the midwest's fluctuations in humidity, but the layout is located in a garage (air conditioned) on a lakeshore. I've been using heavier than normal bracing as well. Maybe overkill, but I'd rather be safe.

[deemery]

If you want to be really safe, seal the edges as well as the sides.


dave

[Dave K.]

Was just thinking about that, Dave. Thanks a bunch for the input. 👍🏻

[bparrish]

Here is an experiment that shows what happens to wood when only painted or sealed on one side. 

Take a kitchen sink sponge.  Let it dry out completely. Press it absolutely flat.  Then pour a small amount of water on your counter top and place the sponge it.  The wet side will swell up and bend the sponge.

Sealing both sides stabilizes the wood so as moisture or humidity moves around both sides will be affected equally.  The shape will be unchanged.

See ya
Bob

[Dave K.]

Great visualization, Bob. Thanks! 👍🏻

[donatode]

Wood is known to absorb moisture.  Woodworkers and furniture makers have known for a very long time to apply finish (wet) on both sides of the wood, even if one side is not visible.  The moisture applied to both sides of the surface counteract the swelling that would have taken place if only one side received the finish. 


In our applications, if you are going to apply an AI wash to the outside, then you should at least apply the same AI wash on the inside....or rattle can it black (or any color).

[Mike Engler]

Does AI seal as well as the spray paint? The AI dries or evaporates so quickly I would question its sealing potential, but then I have a very limited knowledge of chemistry. Maybe AI on both sides, then spray paint one side and acrylic or whatever on the other, or is this overkill?


I spray the black not so much for future lighting, but to prevent seeing the lack of interior detail when there are windows on two or more sides. I also add black on both sides cardstock for view blocks.


I also am from the school of "you can't over-brace" structures. That's why I try to be first in line at the Mt. Albert booth when Gerry sells his bundles of odd size strip wood "seconds" for bargain prices.

[bparrish]

Mike .....

Good questions. AI is a color with no sealer or finish. The alcohol serves two functions. It is a diluting agent and more importantly it is a carrier.  That means a liquid to get a pigment onto something.   Almost all wood stains are some earth colored clay in an oil base as a carrier.  Minwax, for example, uses a mineral spirit and linseed oil as a carrier. In addition the company puts in some thinned varnish that is at best a sealer.

AI with its alcohol carrier leaves nothing but the blacking pigment that I think is nothing more than lamp blacking. It has no sealing capabilities. 

If anything like dull cote is used then it is best to do both sides. It is a sealer / finish in that application. 

See ya
Bob

[Dave K.]

Wonderful contributions, guys...thanks so much! 👍🏻

[Mike Engler]

So my take on a wooden building would be:


Individual boards, or board-on-board- stain both sides of the stripwood with whatever you stain with.


Board and batten, scribed siding, or clapboard sheets or die-cut pieces- black rattle-can on inside walls
and maybe rattle-can khaki followed by acrylic paint on outside? Could try your peeling paint methods!


I have a lot of structures that are AI or AI and chalk on both sides that are well-braced that haven't warped, but for the most part they have always been in climate controlled inside locations,

[ReadingBob]

Interesting discussion.  We have a little humidity problem down here in Florida.  It warps everything.  Even me.      

Since I moved here and most of my structures are stored in the garage with no climate control I fall into the school of you can never brace too much.  The only time I encounter any warping issues is when I apply the A&I wash or thinned acrylic paint wash during a build.  Then I figure out where I may need to add some additional bracing to straighten things out.  Fortunately I've never had a finished structure, stored in the garage, suffer from any 'post build' warping issues.     

[Dave K.]

Count me as a member of Overbracers Anonymous.

[bparrish]

Gent ...

I'm an interior guy so I try and minimize bracing when I can.  Perhaps living in downtown Idaho gives me an unfair advantage. 

I do use bracing hen I can.

See ya
Bob