Skinning TD In Hot Sun or Cold Garage

[OkieSailor]

A question has occured to me. Is there a difference between skinning a TD in the hot sun or the cool shade of the garage. Does a hot skin expand enough so that if you installed it hot, when it cooled down, would it shrink enough to cause problems? Such as pull fastners loose?

Conversly if you installed it while very cold, does it expand enough in the hot sun to cause problems? I know I saw a remark about aluminum skins getting hot and popping loose from contact cement and the wisdom of "floating" the skin and letting side fastners hold it in place.

[doug hodder]

I've got some of the same questions. I spoke to the guy at RW Johnson, has a web site selling tear parts and he mentioned that he uses a flooring adhesieve. It trowels on thicker than the contact cement and gives you more working time to maneuver things around. It also tends to squish so that you get better contact. My experience with contact cement, from counter tops is that it is pretty much one shot, and you don't get a chance to remove it without breaking up material, at least on counter tops. I have used carpet type glues for marine carpeting in boats. Has anyone done this on aluminum skin? Maybe I'll do a test. I'm thinking that the interior of the skin would need to be scuffed, could be done with a belt sander. Any ideas or opinions????????? Okie, I would think that you would want to apply glue and skin at a moderate temperature. Anything done too cold could be an issue 50 degrees warmer, same thing with colder. I don't know beans about the expansion coefficients of a piece of aluminum that size though. Doug Hodder

[San Diegan]

Hot or cold, I've heard that having a can of laquer thinner handy to take the whole skin off in event of an unworkable situaltion is possible. It does seem to dissolve the contact cement and evaporates away without a residual in the wood. I have done this with small scale projects such as applying a laminate to a small structure. Scaling up to a 4' x 8/10' aluminum skin would require some caution about fumes, ignition sources, and skin protection. Hopefully, if you are working with an adhesive or contact cement, you are already being very careful.

Tom

[Grant]

My suggestion ...

Hot sun & "float" the roof and hatch skins. I like .040" here.

Shade of the garage and a soft-setting glue (RV ruber-roof adhesive, vinyl top adhesive, Sikaflex, etc.) for the side skins. A good choice is .032" or .040", but if you have a really straight & smooth sheathing, you can get by with .024"

Good Luck, and ...

CHEERS!

Grant

[OkieSailor]

NOT a good idea. One spark and you will be very very unhappy.

Without going into details I once removed a 4 ft X7 ft piece of 1/16th inch brass skin from a vault door. Myself and another man, using a 50 lb guillotine style blade, about a 2 gallons of laquer thinner and 3 vent fans pulling air out of the bank and one pumping fresh air in, removed that skin. And then installed a replacement skin. You do not want to have to do this type of trick.

Try this trick though. Cut a number of 1/4 inch thick boards from a 2x4 about 6 inchs longer than the width of the area you are working with. Apply glue to panel and to TD. Lay boards across TD after contact cement no longer tacky. Hold boards in place with masking tape. Lay skin over boards being VERY careful the two glued surfaces do not touch. Carefully line up skin and start bonding at one end. Work your way across surface pulling boards one at a time until you get to the end of the skin. If you lined everything correctly BEFORE you let the two surfaces touch you should have a perfectly aligned glued on skin panel. Make sure Nothing in the way of splinters from the boards, extra masking tape or just plain trash is on either surface. a whisk broom will sweep areas clean as the contact cement will not hold the trash.

I do like the idea of the "softer" glues that give working time better than contact cement.

Rots of Ruck!!

[Grant]

"I do like the idea of the "softer" glues that give working time better than contact cement."

Maybe I don't need to say this, but just as a reminder, the reason for using a soft-setting glue isn't so much for better working times (although that IS a plus!) as it is for the flexible bond it provides that gives the aluminum an ability to "squirm" (expand and contract under different temperatures) without delaminating from the teardrop. Under not-so-extreme conditions, I've watched aluminum skin that was contact-cemented to plywood delaminate the top layer of the plywood after only a couple of hours sitting in direct sunlight on a not-so-hot late-Spring day. One lesson learned the hard way ...

CHEERS!

Grant