laun plywood explosion

[CASHCOW]

Howdy to all! started putting the "laun" plywood inside my TD yesterday. The first piece went in like a dream. BUT when I got to the front piece..BOOM!!! Exploded like a balloon. Why didnt someone warn me..... !
I dont know who came out of the tear faster...me or the plywood.

Anyway, tonight I got smart...at least smarter (I think)...got out the ole router and put in relief cuts in every inch and it fit like a charm... SO newbies be warned..... if you dont make relief cuts in your laun plywood, you better wear body armor!
DUH! live and learn........

[halfdome, Danny]

What is the thickness of your ply? Danny

[doug hodder]

I did.....right here...sorry about that. Watch what you get, there are a lot of really crappy plys out there on the market. Doug

http://tnttt.com/viewto ... 72&start=0

[Gage]

That's one reason I get my ply from a lumber store, not Home Depot or some other store like that. When I was building the Scotsman I was going to do a round corner on my inside cabinet. Changed my mind and went with a shelf. But I did a test piece 4' wide x 3' long and with the help of some water I bent it to a 4" radius and no fracture. But I wouldn't try it with 1/4". Something to think about.

Oh, and I'll bet you beat the ply out.

[nikwax]

I just did the outside of my TT, 1/4 ACX with a hardwood A face. A 36' radius was barely possible with kerfs and I have one small crack in the face. For the 24" radius, kerfs and water, then a bending jig. Pretty tough stuff.

Luan is notorious for its variable quality. The good stuff is expensive.

[Miriam C.]

Some of us are lazy. I used 1/8" birch. Bends like a dream around a 12" radius but you have to do it slowly and gently.

[halfdome, Danny]

Some of us are lazy. I used 1/8" birch. Bends like a dream around a 12" radius but you have to do it slowly and gently.

Not lazy, just smart, the most bang for your bucks. Danny

[Gage]

Some of us are lazy. I used 1/8" birch. Bends like a dream around a 12" radius but you have to do it slowly and gently.

Like Danny said "not lazy, but smart". Your doing/did great there Miriam. It's been said many times here on the board. You don't need 1/4" ply for your skins. That's unless you like a lot of work that's not necessary. Formed 1/8" is plenty strong and besides, the last time I check. No body on the board was trying to build a house. I think what all new builders should do before they start thier build is go visit an RV mfg to see how they build or skin thier travel trailers.

It's strange how questions are asked and qualified answers are given by some that have engineering knowledge are just over looked. Because the answer wasn't what they were looking for. And then wonder why they are having problems.

Formed this skin with no water or extra cuts.

[jeepr]

The thinnest I have been able to get is 5.2mm luan. I even went to the lumber store and the guy looked at me like I had a third eye when I asked for 1/8" ply. Hopefully it will bend OK, it seems pretty bendy and I am going to be going across the grain.

Thanks for the heads-up, I will let you know..

[CASHCOW]

appreciate the info Miriam. I think I will go to that route when I am putting on the outer skin.

When we wrote the first post on this particular subject, I was laughing so hard at what had happened, that I wanted to share the info with other newbies to keep them from making the same mistake as I did.

I guess I didnt realize some of those reading it would take what I said so SERIOUSLY...... The post was meant to be comical yet informative.

And yet, I come away feeling "stupid, lazy and ignorant"........ well...I wasnt being "lazy" and I wasnt "ignoring advice that was given..." To be honest, I had actually read on quite a few posts that luan plywood was what I was suppose to use. Guess I misunderstood or something.

Oh well, it was still very comical and Brenda wishes she had had the video camera running!... Back to the garage to glue, nail, screw, and dream.

[halfdome, Danny]

And yet, I come away feeling "stupid, lazy and ignorant"........ well...I wasnt being "lazy" and I wasnt "ignoring advice that was given..." To be honest, I had actually read on quite a few posts that luan plywood was what I was suppose to use. Guess I misunderstood or something.

Oh well, it was still very comical and Brenda wishes she had had the video camera running!... Back to the garage to glue, nail, screw, and dream.

Mike don't take it so personal no one was slamming you. From your original post you said.

Anyway, tonight I got smart...at least smarter (I think)...

If ever in doubt please ask and you'll get plenty of answers as you know. FYI Luann is basically thin mahogany with two layers of veneer and was never intended to be used for radius work, that's where veneer core comes into play. Danny

[Mark72]

I was looking for a pic of this but I must not have got one in my rush to get to turkey run. My Jim Dandy build has 16" radius on both ends. I used 1/4" luan to skin over the roof spars. While messing around with the luan I found a sheet that looked like mahogany but it had worm holes all over it. I asked one of the employees there what it was. He said oh that is a waster, just a cover sheet put on by the manufacturer to protect the rest of the stack. You can have it if you want,ok. When i got it home the regular luan was way to tough to use on my rear radius so i tried the waste sheet and it worked great! that sheet had a good solid core ply and wormy plies on the outsides. It was almost like bendy ply.

Mark

[CASHCOW]

it is amazing what we can get from the lumber yards for free if we just think to ask. Used to have some friends who owned a lumber yard and it surprised me at what they called "waste".

anyway, got the inside all "plywooded" tonight and am looking forward to the next "chapter" of this project. Thanks again for all the advice. wouldnt be able to get very far without it......