Oilcan Top

[island45]

I have not driven my current lpb with the top on it yet, but I've had 2 before that bonked up and down when I hit potholes on the dirt road into my place. One top was so bad that i made a hardwood bow and sprung it into place so the steel wouldn't fatigue and crack. With fall approaching I'm gonna start fixing and painting my doors and top and figured now is the time to address the oilcanning issue. How have others fixed this? any pictures?

 

[3_puppies]

mine's pretty stiff, no flexing that I can remember

 

[Landpimp]

I like your original mod.....its still in place with a piece of foam added so it makes less noise

 

[island45]

It did work pretty well, but thought I'd like to improve on it. I've found that once I start driving a rig I never get around to fixing all the things I was gonna do. And now here I find myself dreaming of next winter's project. Hmmmm '79 fj 55 factory ps and 3.70's. first off, remove that rotten body......

 

[dr_claw]

I was thinking about this too. A single band of 16 gauge on edge is probably what I will do. I won't be running a headliner, so we will see what it will look like.

 

[island45]

That would look the most like factory. I never seem to have a headliner either. Would you cut this to shape or bend it? I guess the curve would be too much to hope for bending it on edge. If you do yours, please post up a picture.

 

[Toyrod]

I used some kind of shrinking tool on my 45 swb. It was a 110v gun that is used to attach the studs to sheetmetal so you can slide hammer dents out without drilling holes. Its other function was to heat up an area about the size of a dime to red hot. I used this on the edges of the top that were floppy. Like every 3 inches. Heated, cooled with a damp rag. It shrunk the metal just slightly and cured the tin can effect. Careful use of a oxy-fuel torch will do the same thing. Just do one spot at a time and let the metal cool COMPLETLEY before you do another. I only had to do 4 or 5 spots on the entire roof to tighten it up.

 

[dr_claw]

wait a month or two and check my thread for pics of this mod. I have to do other things first though

 

[island45]

Toyrod, where do you do this heating? On the flat surface on top of the roof? Just above the gutter? I really don't quite understand the principle involved here. A photo of the roof perhaps with tape stuck on where to heat? Thanks. That would be the best repair and it's still as built. Thanks!

 

[island45]

I'd like to do this heating before painting, so can anyone tell me where to apply the dime sized hot spots?

 

[malcb]

The heating shrinks the steel, best thing is to get a bit of gash steel of similar gauge make a shallow dent in it and see if you can shrink it out.

I would guess the heating on the roof would need to be on the flat where it's floppy, the corners and bends are already stiffer.

Just don't heat it too much and burn a hole.

 

[malcb]

Here's a link to an amazing bit of work I bookmarked a while ago. The wleding is not relevant but notice how he talks about "stretching" the metal around the weld because it has shrunk, same idea in heating a dime sized area of the roof - like tuning a drum to get it taut!

http://www.fergusoncoachbuilding.blogspot.com/

 

[Toyrod]

Roof repair

I'd like to do this heating before painting, so can anyone tell me where to apply the dime sized hot spots?

I will get some pics this weekend and show exactly where I heated.

My SWB had a soft spot about 2 feet in diameter over the passenger side. I heated 4 or 5 spots on the perimeter of this soft spot.

It is important to heat one small spot until it just turns red. Then briefly wipe the heated spot with a damp rag to keep the heat from migrating. Wait for the entire panel to cool to room temperature before you do another spot on the opposite side of the area you are working with. You should notice some results with the first one. Do just enough to get rid of the oilcan effect. If you shrink too much metal, it will pull other areas of the roof and cause you additional problems.

Do not try this with a propane torch or similar device. You will heat too large of an area trying to get your dime sized red spot. I have shrunk severely stretched metal by drilling a 1/8 inch hole and mig welding it shut. This is risky because you don't have as much control over how much you are shrinking.

Somebody made a good suggestion by practicing on a piece of scrap metal. Beat the crap out of a piece with a hammer then flatten it out the best you can. Shrink a couple areas to learn the effect.

Also, make sure the metal is bare and clean.

Brian

 

[Toyrod]

Here's a link to an amazing bit of work I bookmarked a while ago. The wleding is not relevant but notice how he talks about "stretching" the metal around the weld because it has shrunk, same idea in heating a dime sized area of the roof - like tuning a drum to get it taut!

Ferguson Coachbuilding

Excellent link! Anyone doing panel work should read this.

 

[24HOURSOFNEVADA]

My 1980 45 came from Oz. with a ladder type brace running front to back. It has a slight bend to it. I didn't know what it was (It looked like a perfect place to slip some mail) and took it off when I took the top off. When I put the top back on, I left it out. After driving around one winter without it I know understand what it is.


As soon as I find my camera I'll post some pics of it. It is really well made and works very well.

 

[island45]

Thanks for all the help, guys. Are you saying use an oxy-atcetylene torch but not propane? I can do that. I do like the ladder type brace as well, and if I do a bad job shrinking the roof, I can always retro the inside mail rack.
Ironically just last night I came around a corner after picking up a friend and he said "that looks like somebody's mail in the road". Sure enough it was mine... with a rubber band around it. It had slid off the seat on my way to his place. Perhaps I need some kind of mail rack that stays on in the summer.

 

[Toyrod]

A propane torch will heat too slow, causing too much heat in too much area. You could kill the metal's temper in a large portion of the roof. I don't know how to fix that.

 

[65swb45]

The 65swb never has oilcan-ed. Neither did my 64lwb, until I set the roof upside down while I was repairing a dent! My buddy's 65swb had been oilcanning for years, so at least I was aware of the phenomenon.

So when it happened to my daily driver, I knew that it was NOT something I was going to learn to live with. I took a single piece of 1/4" steel rod, bent it with a slight arc, and welded it into the center rib of the top on the inside. The rib is tall enough that the rod fit almost entirely within the 'trough' inside the cab. I fiugred if one was not enough, I would weld rods into the other ribs as well.

One was enough.

BTW, this is a really cool tech thread for the 45 forum.

Best

Mark A.

 

[Toyrod]

Here are some pics. It rained all weekend so I wasn't able to mark the top out like I should have. The rubber hose represents the area on this roof that is collapsed. The rocks show where I would do the initial heating. I would start with the center of the back of the roof and then one on the front. Then to the back again.

The weather is supposed to straighten out next week. I will update these photos with some better representation.

 

[Kief]

I've been fixing a nasty dent on my '75 hood. I was using a torch to shrink but didn't know about doing one spot and then COMPLETELY cooling the metal down. It turned out pretty good I think. Do you recommend working all the dents out first and shrink any consequential stretching as well?
I have hear guys say they used compressed air to cool.. seemed slow to me.