bending 5.2mm luan(need some advice)

[stjohn]

went and got luan and insulation today to skin the top heres my problem I've got a 15" radius curve in the front how is the best way to bend it around corner ie cut knotchs ,wet it ,bend it a little at a time,I really need to here from the great gurus on this (or at lest someone who nows more than me that means 99.9% of you)thanks in advance to all that reply

Mike

[tonyj]

I used 1/8 luan, which should be slightly thinner than the 5.2mm you are using (although they might be the same thickness-I didn't measure, just assumed it was an eighth).

First, you might want to consider bending on the 4 foot width. If you do, that means you will have to cut your sheet in half. I bent mine on the long side when I put in my ceiling, and it groaned and creaked and cracked. And my radius was 19 inches. I know others have said they have wet the sheet, and some have tried heat. They have done it with 1/4 thickness, but I don't recall if it was on a radius as tight as 15.

Hopefully someone will reply who has bent that tight a radius. Just take it slow and don't force it, or that luan will crack. I also had luck using rachet tie down straps for cinching the sheet down. It applies good, even pressure around the curve.

Good luck.

[Gage]

Are you going to skin it with aluminum?

Have a good day.

[stjohn]

No Gage just wood and paint

[asianflava]

I had to use a metric conversion website: 5.2mm = 1/10in.

I used 2 layers of 1/8in luan to skin the outside of my tear. The bottom of the hatch has a really tight radius on it (not shure what it is exactly) but I learned a couple things. Make shure you are able to clamp/glue/staple the entire edge down before you start to bend.

Starting with the tight radius, I layed down a bead of PL polyurethane caulk and I clamped down the bottom edge with brads and a 2X4 on top. After it setup I pulled it back a little, and put more caulk down close to the last bead, then I put the rest of the panel down.

You can probably start at the bottom, and work your way up. Stop short of the arc and make shure the skin is down good. I used a 2X4 on edge which was held down with a ratchet strap that went around both doors. As long as you can get one side of the arc under control before you start the rest, you should be fine. Just test fit to make shure the edge of the panel hits as far as possible from the center of the arc.

I hope I explained this well enough.

[Gage]

Well if your going to paint. Lay the luan across the tear. Don't try and run it length ways. Then get some good wood filler/bondo and blend in the joints. Sand, paint, sand, paint and sand some more. Then paint your final coat. That would be one way.

Have a good day.

[surveytech]

I used 5.2mm luan for my 24" bends and it bent easily. I did find a big difference in the luan from Home Depot vs. Lowes. One was way way more flexible than the other.
You will have to bend it across the 4' side though. I have two seams on mine that I filled and sanded with Bondo. Take your time with that and the seams will disappear.
Also best not to put a seam on a curve. If you place them on the flat areas of the tear you will find it easier to get a good looking seam.

[dacrazyrn]

I did a 12" and an 18" radius across the front of my tear. A system that boat builders use and came from someone here.
I boiled water, layed the piece on large towels on the ground and then coverd them with large towels. Dumped some ammonia in the "boiled" water and dumped her on. I only wanted to do this with the sheets I had, so I repeated the process a total of 4 times (times on each side).
got the glue ready, some screws. Layed the end up there (I put the length wise oriented grain DOWN and the crosswise UP towards me-seemed to bend easier and not stress) and got it lined up, shot some screws on one end. Hit the glue gun all up and down the spars, grabbed the staple gun and started slowly rounding it around the corners. Stapling as I go. Screwed the other side. It is holding so far.
Page 4 in my album shows some pics.

[Steve_Cox]

Mike

Here is a picture of 1/4 inch oak, and less of a radius. Like comparing apples and oranges I guess. I just used epoxy to put it on, no screws, nails or staples.

[imstriker]

I used HD Luan along the 4' width on my roof. I attached the bottom portion, then steamed it with my wife's former iron. I say former because she oddly did not want it back afterwards. That seems to have helped, or at least did in my mind. Then I stapled down the edges as I bent it.

[madjack]

....then steamed it with my wife's former iron..

...you know, I seem to remember Sir Lar of Wyn saying something about using one of those home steam cleaners (and some Guiness(?) when he applied/bent his ply .........
madjack

[Classic Finn]

If you remember I bent 4mm ply in the Sauna.. And Im willing to bet that
your 5.2mm luan would bend to shape the same way .... If Id give it a try in the Sauna on a weekend.. Mike Cmon over to Finland we,ll get it bent.

Steam will bend it for sure. It would have to be steamed a little longer than the 30 minutes I had the 4mm in it. I didnt let the ply cool all the way either before installing it.. No damage occured nor any water stains of any kind.

Classic Finn

As Madjack mentioned - If you could get a steamer of some sort to do it with..

[imstriker]

As an addendum... I just picked up a Scunci steamer this weekend at Big Lots. Seems to put out a ton of steam for 30 bucks. I wish I would have had it instead of the iron.

[stjohn]

WELL 5.2 MM luan will bend around a 15" radius but it's tough the first piece broke (that means a nother trip to lowes)the 2nd we wet very much along the bend put some strips down along the spars worked our way down it only made nois once in the middle of the bend Now how long should I leave it bent before I remove it and install it permently here is a pic of the bend team (I had to feed them all tacos before they would help me pretty cheap labor though)

this is my wife,son,daughter and daughters boyfriend(aka that damn boy


thanks for all of your help also

MIke