Phone case

I have wanted one of those awesome wooden phone cases since the first time I saw one. Alas my phone is not of a popular model and I am in no position to get a new one.(plus I like my phone). Then I realized I have a shopbot!
After cutting and tweaking 4 renditions of my case I got everything lined up perfect and even managed to make buttons for it as well. I left it overnight and it stayed nice and flat so I proceeded to finish it, 3 coats of clear good enough for me but as the clear dried both pieces began to cup and now it doesn't work.

This one was made from pine as pine is cheap and I knew I'd be recutting it a few times, I am going to make one out of some red oak but what can I do to keep it from cupping?

Hi Tom,
did you coat the inside and outside., if not you need to coat the inside and out side with the same number of coats. A guy I new was making humidors and that is what he found to be the solution. Hope this helps.
Don

I did coat both but only one coat on the inside, I didn't want any built up clear coat to effect the dimensions as the tolerances are very tight.

I just cut the new one from red oak and besides cutting much nicer it seems to be holding its shape better to. Also decided to finish it with teak oil so I am rubbing it in inside and out.

That being said I thought what made a humidor work is the raw cedar on the inside. both of mine that I purchased are raw on the inside. It would be good to know as I plan to create my own much more display worthy humidor

Thin stuff is sometimes hard to stabilize. I've liberally soaked thin parts in shellac to plasticize them before machining them. You can try a purpose made wood hardener like those sold for turning spalted wood to stabilize it - that penetrates into the wood and plasticizes it probably more effectively than shellac - which may be a little too thick unless you are mixing your own from chips or old 78 records ;)

-B

If you are very serious about it and don't mind the effort you can vacuum stabilize the wood, e.g. with the Cactus Juice brand resin. I believe this is a heat curing PMMA type resin and can be dyed. It is not cheap and quite a mess, normally used for pen turning blanks and the like. But it fills all the wood pores solidly with plastic.

rubbed it with the teak repeatedly all weekend seems to be holding shape, I will post a pic as soon as I get a camera that's not my phone!