Heating New Skins Before Riveting???

Highway Yacht · March 01, 2011, 01:09:08 PM

I'm planning on installing the new skins within the week on my MC-9. I am using 1/16" (16 guage) flat steel sheets in 10 ft lengths. The temps here are planned to be in the 60's this week and mostly sunny. I've read that most new skins need to be heated during winter months with a forced air heater before attaching to the bus to lower the risk waves in the panels. Seems like a lot of people that use the heaters have sometimes used a thinner skin and some even use a rolled out material . My question is: What are the chances of having wavey skins without using a forced air heater on the flat steel sheets with a 1/16" thickness that I have? I can easily lay them out in the sun for a couple hours but not sure that will be enough. The reason I am asking is because I don't have a forced air heater and would hate to buy one if not really needed.

Thanks,
Jimmy

luvrbus · March 01, 2011, 01:44:09 PM

Heat those and stretch or you will have waves man I hate those waves

good luck

Utahclaimjumper · March 01, 2011, 03:06:07 PM

If you do that then do so BEFORE drilling the rivet holes or you do yourself no good.>>Dan

JohnEd · March 01, 2011, 05:53:38 PM

Heat it for sure. The criteria is to get a sufficient delta between the skin and the bus frame. Hoter'n hell is one that I heard but I couldn't find that in kelvin. Safari used banks of heat lamps once they learned about this but that was after they made oodles of them.

The waves look really crappy but a lot of Knuts met their match with this issue and just went ahead and riveted the sides on the frame.

John

chart1 · March 01, 2011, 05:58:13 PM

Don't buy one just rent it if that's all you need it for. Sunbelt rental is nationwide.

Utahclaimjumper · March 01, 2011, 06:08:53 PM

You wont have as much grief with steel as with aluminium, I did my 06 with 16 Ga. steel in the summer with no problems in any temps since.>>>Dan

Highway Yacht · March 02, 2011, 04:34:57 AM

Quote from: luvrbus on March 01, 2011, 01:44:09 PM
Heat those and stretch or you will have waves man I hate those waves

good luck

I'm going to go ahead and buy a good used forced air heater. I can buy a used one for about the same money as the rental rate of 2 days from Sunbelt. Big Question for you ---> "Hows the best way to stretch flat steel sheets??" I've stretched wire fencing, cables, and even coiled steel with a come along winch.....but never knew you could stretch flat steel.

Thanks,
Jimmy

Len Silva · March 02, 2011, 04:46:44 AM

I can just pass on my experience in helping to skin several Eagles. I was just a grunt in this operation. We used aluminum but I think the process would be similar using steel.

A single length of aluminum was securely riveted at the front and extended about three feet past the rear of the bus. A clamp was fabricated from angle iron and bolted to the rear end of the aluminum strip. It was then kept under significant tension using a come-along.

We then used a propane weed burner to heat, drill, and rivet, moving from the front to the rear and always maintaining tension on the metal. This operation took four or five people but worked great with never a ripple.

Utahclaimjumper · March 02, 2011, 04:57:27 AM

You won't be "stretching " in the traditional sense, just warm it evenly to a point that's its warmer than the bus frame, steel does not expand as much as aluminium and is much easier to work with.>>>Dan

luvrbus · March 02, 2011, 06:36:36 AM

I agree with Dan about the steel vs aluminium or fiberglass and the short sections but I did over 40 foot sections with no rivets and steel will wave if not heated and without tension or stretching applied as I call it

good luck

Skykingrob · March 02, 2011, 07:36:52 PM

Jimmy
I cannot speak to steel but I can tell you what we did with aluminum on our Prevost. It was a seated coach and I removed 10 windows from the mid section. I then had a local machine shop form 5x10 aluminum sheets. I took the formed sheets and laid them in place. I riveted the upper left corner and another rivet about 1 foot away, just enought to keep the panel from sliding off with the added weight mentioned below. I then added a bolted in weight of 50# in the mid-lower section of the panel. I had the wife stand inside the coach with a propane weed burner purchased from a farm supply store (orschlands) and heated the panels until they were way to hot to touch. When I thought it was not going to expand anymore, about 15 minutes of high heating, I drilled and riveted the top right then lower left and lower right while she kept heat on it. She liked it because she could enjoy the heat since like many women she is always cold.
Have not seen any waves with this process. The weed burner is much cheaper than the heater, about $65 at my farm store.

Rob
91 Prevost LeMirage XL
Missouri