| Author |
Message |
John Biundo (Jbiundo) (64.175.36.81)
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Votes: 0 (Vote!) | | Posted on Tuesday, May 28, 2002 - 4:51 pm: | |
I have a few questions about re-skinning my MC9.
I'd like to go with steel, and I plan to cover it with fiberglass.
I was thinking of 18gauge, but I'm having a hard time finding that in galvanized. So far, 24gauge seems to be more common in galvanized.
By the way, I assume galvanized is the way to go? Any other specs I need to keep in mind while shopping (i.e., are there differences in alloys or manuf. process that are important)?
Also, is it critical to make the overlap joints on a vertical frame member? Or could I use some sort of glue and/or sealant (or weld?) and have the joints occur "naturally" every 8'? Keeping in mind that I'll cover the steel with fiberglass, I'm thinking maybe I can get away with this kind of joint... ??? |
Jim Nelson (64.24.85.52)
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Votes: 0 (Vote!) | | Posted on Tuesday, May 28, 2002 - 6:22 pm: | |
Another idea is to use stainless steel. That way you can plug-weld the skins on instead of using boxes and boxes of rivets - welding galvanized is a sure way to zinc poisoning.
It would be possible to make 8' sheets work, but remember that the side skins are a structural part of the bus - the original skins are .063 aluminum (I believe 3003-H14, don't hold me to that, though) using aircraft structural rivets. Without the added rigidity of the sidewalls, the front and rear will shift about and you will have all sorts of interesting alignment, tire wear, and suspension breakage problems. |
Ross Carlisle (Ross) (216.107.195.57)
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Votes: 0 (Vote!) | | Posted on Tuesday, May 28, 2002 - 9:34 pm: | |
I'm using cold rolled 16ga steel. 24ga is way too thin. 16ga goes on nice and straight and it is not nearly as sensitive to temperature changes as aluminum. I was going to plug weld the skins, but at the last minute decided to use rivets. You have to rivet the top and bottom, so welding would not save you a whole lot of rivets. The reason I chose not to weld was because of heat distortion. I did a test and the 16ga distorted a bit from the heat. I though straight sides with rivets would be better than smooth wavy sides.
I ordered 10' x 36" sheets of steel. I had to cut them down to 35". The 10' length will land you on a vertical frame every time. I matched the seams to the aluminum seams in the lower panels. I top and bottom at about 1.5" spacing then at every frame at 3" spacing. Same spacing as the vertical rivets in the lower panels.
Aside from a one piece aluminum skin, I think cold rolled steel is the best way to go. Galvanized would work but it can be tough to paint. Generally, you are supposed to let it age 6 months prior to painting. Sainless would work well, provided you are planning to knock off a bank or something. 1 piece aluminum was cheaper than stainless sheets.
I primed back sides of the sheets with zinc chromate where ever they would touch a frame or overlap. I have not done this yet, but on Friday I will spray out the inside with rustoleum primer. On the outside, just DA sand and pray with a good automotive primer. I like epoxy primers.
Ross |
Ross Carlisle (Ross) (216.107.195.57)
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Votes: 0 (Vote!) | | Posted on Tuesday, May 28, 2002 - 9:38 pm: | |
Forgot to mention...I used Sikaflex under the rivets.
Ross |
Steve (4.3.159.66)
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Votes: 0 (Vote!) | | Posted on Wednesday, May 29, 2002 - 6:15 pm: | |
Jim
How do you plug-weld stainless steel to aluminum??
"Another idea is to use stainless steel. That way you can plug-weld the skins on instead of using boxes and boxes of rivets "
As you said "skins are a structural part of the bus"
I would never weld to the skin, this will cause work hardening, and cracks. |
John Biundo (Jbiundo) (64.175.36.81)
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Votes: 0 (Vote!) | | Posted on Wednesday, May 29, 2002 - 7:52 pm: | |
All - thanks for the suggestions.
Steve - I think Jim meant welding the stainless sheets to the steel frame members.
john |
gabby (209.253.225.28)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 31, 2002 - 12:53 am: | |
i used 22ga jet coat to skin my 4905. it is steel and is primed. comes in 4X10 foot sheets. price was reasonable. i did overlap on the the panels. |