Author Topic: kind of sick to my stomach (Read 1734 times)

Dne' · « **on:** September, 29, 2010, 02:07:48 PM »

I've knocked out some pretty difficult jobs on this stang, but this one has come back to haunt me!

This is probably one of my biggest screwups of my project! I was almost not tempted to show this due to great embarresment! But I need some advice! The story: The roof had/has horrible pitted rust in the beginning. I began by grinding/sanding, progressed to phosphoric acid, went through a roll of 80grit da paper, more phosphoric acid, and it actually looked kind of ok at one time. I used Eastwoods rust converter~ rust encapsulator~epoxy primer, of course the filler is shown in the photo. I was looking at replacing the roof a week ago, but I just dont think I'm up to that. I bought a sandblaster from harbor frieght, but darn the mess. So I've marked off a 1' section, sanded, soaked in phosphoric acid again, and that 1' section looks ok but that was an easy area. The rest of the car was in decent shape.

It's like the stuff isn't rust as it doesn't respond to phosphoric acid like I was told it would! It's like the paint that was on it oxidized or something into a hardened material! Anyway, any suggestions are welcome and appreciated! This is pretty much all I lack to getting the car on the road!
dne'

crustycurmudgeon · « **Reply #1 on:** September, 29, 2010, 02:36:22 PM »

I'm interested in reading the comments about this, as I believe my roof has exactly the same issue as you've described. It doesn't have any rust-through, but it's got a lot of surface rust and lots of tiny pits. The metal still feels very solid. The tops of the fenders are similar but not as bad. You can see a bit of it in this picture, on the passenger side of the roof:

Frank

Dne' · « **Reply #2 on:** September, 29, 2010, 03:15:09 PM »

this is what it looked like in the beginning. You can just make out the roof and the red color. It was very rough, pitted, but like you said Crusty, very solid! I can take 80grit and work on a small area, and come up with red nasty stuff that as tough as nails, but then the nice metal comes through, but with fine pits. When I sand on it, it's just difficult to get it to "give"!
I figure maybe If I can just work a very small area, get it 'cleared', then move on to a next area, maybe I can complete it in a month, but my elbows and wrists are really aching. I tried a 7"grinder with 80grit and it didn't even budge it, but I will say my da with 80grit does move it some, then I blow it off, then sand it again, the red stuff come up, blow it off! I did this a couple years ago, and it was crazy~ that's when I took a big chance, that didn't pay off! :cry live n learn eh!

I'm almost tempted to try my 4" angle grinder that I use on grinding welds! Maybe I'll try a tiny area tomorrow, the weather is so wonderful right now!!

blue65coupe · « **Reply #3 on:** September, 29, 2010, 03:32:37 PM »

Can't wait to see the fix. The truck I'm getting ready to redo has the exact same roof issue.

Choptop69 · « **Reply #4 on:** September, 29, 2010, 06:32:53 PM »

What I would try is 36 grit on an 8" fat pad grinder or on a buffer. Work in small areas as to not get the metal hot. The middle of the roof will be the hardest because there is no support. If the pits dont grind away I would say replace the roof.If the grinding helps dont forget to use a self etching primer, this way it does not rust again. If you need help replacing the roof I can walk you though it.
Cory

Dne' · « **Reply #5 on:** September, 30, 2010, 04:01:22 AM »

THank you Cory! I'll pick up some 36grit today. I do have a buffer too! A roof from a local Mustang supplier is about 325.oo, this is far from what I'd like to undertake, but I'd do it if I have to. I'll post as I go along.
thanks, dne'

Quote from: Choptop69 on September, 29, 2010, 06:32:53 PM

What I would try is 36 grit on an 8" fat pad grinder or on a buffer. Work in small areas as to not get the metal hot. The middle of the roof will be the hardest because there is no support. If the pits dont grind away I would say replace the roof.If the grinding helps dont forget to use a self etching primer, this way it does not rust again. If you need help replacing the roof I can walk you though it.
Cory

Dne' · « **Reply #6 on:** September, 30, 2010, 04:42:33 AM »

This was actually from a couple days ago. I was using my da with 80grit paper. The sides and corners are actually the easy part, it's the middle of the roof that the PITA! Do they make 36 grit for my da? I'll find out today.

daveSanborn · « **Reply #7 on:** September, 30, 2010, 01:02:09 PM »

Dne',

In your efforts to remove the pitting you are in effect "sanding down" the metal surrounding the pits. By the time you're done, your roof could be "paper thin". 36 grit is going to remove metal almost as fast as an angle grinding wheel would.

I hate to say it, but I'd replace the roof. A sawzall with a metal cutting blade will have the old/pitted roof off and an hour later you'll be starting to tack weld the new roof in place. You'd likely have been done by now with much less effort than you've already spent.

Dne' · « **Reply #8 on:** September, 30, 2010, 01:26:37 PM »

I've been doing a little search, but no one seems to carry a roof replacment, or they just haven't make a repop for the coupes yet.

tarafied1 · « **Reply #9 on:** September, 30, 2010, 07:32:08 PM »

there are lots of coupes nobody wants to save, I'd think you could get a roof fairly cheap. Heck if the POS 67 I got from Dave didn't have big holes around the back window I'd donate it. One of the members here replaced the roof, Tony R, here's a link http://www.stangfix.com/testforum/index.php/topic,4238.0.html
If you could get it cut below the factory seams you could clean up the skin and like Dave said, less time overall. Factory skin would be better than a repop too IMO. If you can get the car looking like it does so far, this will be no trouble for you!

Dne' · « **Reply #10 on:** October, 01, 2010, 07:17:39 AM »

That link really helped~ visualization is great, but I'm a little confused~ I'll be replacing just the skin of the roof, not the entire roof? I'm surprized there's not a How To on replacing the roof skin. I'll need specifics on this~ I'll keep my eyes open for a roof.
baby sitting today and not able to sit for long~
bbL
dne'

Dne' · « **Reply #11 on:** October, 01, 2010, 06:48:15 PM »

just got off the phone with Bruce at Surefirerestoration located here in Houston~ he is the nicest guy! anyway, he's telling me, and judging from my photos and what I explained to him, he said sounds like the encapsulator/convertor that I used didn't work together with my epoxy primer. He explained it well enough, something about the acid nature of the converter didn't go with the epoxy primer(that may explain why the paint just scraped right off with a razor blade), plus I should have used an self etching primer on the fresh metal. He instructed me to keep sanding, possibly with a straight line sander using 30grit, and moving the sander not to create too much heat and gradually bring the da back in with 80grit and eventually lesser grit. It's a lot of work either way(replacing the roof vs. not), but I'm not in a great hurry, so I'll just do a square foot at a time. I'll have to get the specifics of what to prime with when I get down to acceptable metal. So, I'm keeping my eyes open for a roof just in case, never know.
dne'

tarafied1 · « **Reply #12 on:** October, 02, 2010, 08:38:49 AM »

Quote from: Dne' on October, 01, 2010, 07:17:39 AM

That link really helped~ visualization is great, but I'm a little confused~ I'll be replacing just the skin of the roof, not the entire roof?

Yes, I would not cut the structure. Without a lot of fixtures to hold the car square, you could have a real mess. Just the skin. As you can see here, he cut/drilled out spot welds and replaced the skin much like you would a quarter panel or cowl.

Dne' · « **Reply #13 on:** October, 02, 2010, 06:31:07 PM »

OMG! how many spot welds were there? :craz I'll post some photos of what I'm trying before doing the roof skin replacement. My thoughts were always~ if the body holds up for a couple years, and then just rusts beyond my ability to repair, I'd look for another rolling chassis that's been painted already and transfer everything from my stang to it, granted that my body is still holding up! lol

buening · « **Reply #14 on:** October, 05, 2010, 06:57:17 AM »

Dne', is the issue getting the rust off? If so, why don't you look into a local place that does soda blasting? I wouldn't think it'd take too much $$$ for them to only do the roof. With all the time and money you'll have into sandpaper you could have it soda blasted and then you could etch prime and sand. A build up primer would fill in the pits. I'd really advise against using that aggressive of a sandpaper on the roof structure. Its likely already thin from the sanding that has occurred, and using more aggressive paper will get it so thin that your roof will likely buckle/ripple eventually.

stangg · « **Reply #15 on:** October, 05, 2010, 09:26:10 AM »

Soda blasting does not remove rust... Personally I would sandblast and epoxy prime it given your goal to have it last for a few years at a minimum...

To minimize the mess, get a plastic tub from one of the big box stores, cut a few holes in it... one on the bottom to tape a plexiglass viewing window, one to stick the blast nozzle through, another for a vacuum. You could set the box up and blast a small area at a time. Tape the box down or put some weatherstripping on the large opening (facing the roof) to keep crap from escaping. If you can get a light in there it would help too. Use low pressure to just get the area cleaned up... I wouldn't worry about getting every last pit perfectly clean just get the junk out of them. Low pressure and a larger distance shouldn't hurt the roof at all. As soon as the area is clean, either self etching primer or an epoxy primer should seal it up enough that you won't have to deal with it for several years if not longer... Epoxy will seal it way better than the original paint did.

Dne' · « **Reply #16 on:** October, 05, 2010, 10:11:56 AM »

Just want to thank ya'll for your advice and help! I used one of my vacuum attachments to suck up the sandblasting media and it works very well! I've got a couple more larger areas to work on, and maybe by the end of this week or next I should be able to epoxy coat it! I'll post some photos after that's accomplished~
dne'

stangg · « **Reply #17 on:** October, 05, 2010, 10:51:00 AM »

I like it !!!

mustangstofear · « **Reply #18 on:** October, 05, 2010, 01:32:02 PM »

Plastic media would take your surface rust off. Sand on the other hand would warp it for sure. It would be a total waste of time and money to replace a roof in that condition. Rich.

Choptop69 · « **Reply #19 on:** October, 05, 2010, 06:51:05 PM »

This has to be one of the best homemade tools ever. I have bought the box and blaster. Now just to find time to use it. Thanks

AzPete · « **Reply #20 on:** October, 05, 2010, 06:59:49 PM »

Leave it to a StangFix member to develop a tool that can suck and blow at the same time..... :craz

Tony R · « **Reply #21 on:** October, 05, 2010, 07:27:40 PM »

I replied to your E-mail. Give me a call if you need any answers. I only replaced the skin. I left the structure in place. I think the replacemen only cost me about 150.

Kats66Pny · « **Reply #22 on:** October, 06, 2010, 06:00:55 AM »

That's a cool gadget! Dang, I really need an air compressor. You're giving me idea's how to sandblast area's on Gertrude in my little garage now. :vic