911 T bare metal. Best way to combat rust?

[carreraplanes]

Dear All,

I am bare metalling a T and would be very grateful for some guidance from the assembled Pelicans.

I have paint stripped the doors, fenders, and lids. I also ran round the insides of the panels with a rotating wire zipper brush on my angle grinder.

The paint will be applied by the local body shop with me flatting it down between coats. They will do any filling necessary but all basic metal prep is up to me. I am however totally paranoid about the rust coming back through. It is mostly light surface corrosion. The only pitting is around the headlight bowls.

I see from posts that some Pelicans are using the Por - 15 and metal ready products. I have discovered a UK outlet for these but really do not have the foggiest on how to use them. I would also be interested to know what peoples experiences have been in the long term (does the rust eventually come through again or cause any long term adverse reaction with the paint?). Or is there a better solution?

The reason for my paranoia is that I live in the UK which as you know is generally cold and damp so the threat of corrosion is greater even with a garaged car.

I have included some pictures of the car which has a fairly interesting history. It was originally resident in Pasadena. A fast buck flipper flipped it into the UK in 1998. He flipped it onto a chap who is the cheif mechanic at the Jordan F! racing team. He carried out quite a bit of work (new carpets, refurbed rims, new chrome). However the car desparately needed paint. He was forced to sell it when he got divorced. So I bought the car and am trying to get it finished so the family can use it over the summer.

The paint looks worse than it appears in the first pic. The one of the lid shows my efforts with wire brush on the inners.

Thanks to you all in anticipation!!

Keith.

911T

RS rep.

[sgat_555]

Have a look at this link:

http://www.911classic.co.uk/workshop.htm

Chassis galanising could be an end to your rust problems.

I have been in contact with Garry many times and he really knows his early Porsches.

Cheers, Stuart

[Wil Ferch]

As I understand it , the chassis galvanizing process is much like any other, leaving large galvanizing "flakes" texture on the suface...entirely suitable for chassis and such, but you need a finer grain structure to be the bedrock of a paint job for exterior body panels...right? That was the special magic of the Thyssen steel used by Porsche when they galvanized.

Wil

[Zeke]

IMHO, one has to dig out the last remaining bits of rust. Sand blasting the offending area will do the trick. I micro blasted every last spot, meaning I circled each with a pencil line, donned the gear and went after each little spot or area one by one until there were no discolorations as evidence that any rust was remaining. On the underside of parts, and in hard to reach areas, phosphoric acid treatment followed by the POR 15, or similar, should curtail further rusting. Be aware that any pinhole to the exterior surface is a breach and will show up in your paint one day.

[Oldporsche]

I have read in Jaguar Magazines, that even a heated garage in the UK needs a dehumidifier.

There are many etching primers that you can use that will be helpful in you quest. I wouldn't leave any bare metal. The Porsche restoration experts in San Antinio Tx,(it's very hot and dry there) tell me that after paint removal, they immediately primer anything. This is because no matter how much metal prep is used, the metal will rust. I have followed their advice on any restoration and have had very good luck. Some of the pieces that I restored were done 20 years ago, and have been kept in my basement, which is not water proof.

I wish you luck in your elements.

David Duffield

[buster73]

I always get nervous when I see pictures of bare metal panels. Don't let them lie around for more than absolutely necessary. Even a couple of hours in a moist climate and you will have new rust seeded on the panel. The panels should be protected a.s.a.p. after removing the paint. Best would be a good Etch or Epoxy primer.

For removing old paint and rust you can use sanding and/or media blasting. The only way to reach hidden areas is chemical stripping, but great care must be taken to clean and neutralize any remains of acid in the last nook and cranny. Good for individual body panels such as fenders, doors or lids, but questionable for complete body shells.

For added protection you might consider thermal zinc spraying (onto media blasted surface). You basically spray molten zinc onto the surface. Will give a relatively rough surface but also excellent adhesion for primer and paint. Can damage your panels if not done correctly though and will add costs.

[carreraplanes]

Thanks to you all for your replies and advice.

Stuart - I think galvanising would be the way to go for the under body if the shell were stripped right out. However the car is basically sound and really only needs a good quality respray. I have stripped the pans down to please myself that there is no rust lurking underneath. Garry's replicas look great BTW.
Thanks.

Dave and Guenter, I went straight out again and sprayed etch primer on those bare panels and will take your advice with the remainder. I will spray etch on as soon as they are stripped off.

Milt, I intend to follow your advise with phosphoric followed by POR-15 for the difficult areas. I take your point about pinholes breaching the surface. I have only one on the exterior body surfaces around the headlight. This is also the only area on the exterior where there is pitting of any kind. I'm going to cut that whole area out and weld it.

My main concern is that in some places the paint was broken and very light corrosion has taken place in those areas. This is also the case in some areas underneath paint which from the outside appeared sound. When cleaned off with the sander there is no apparent pitting, it is not that heavy. It is however heavier than any very light corrosion that would have taken root over the 2 days that the panels lay around, therefore if all things are equal it is this older corrosion that would be more of a problem. The best solution for that heavier stuff will in theory take care of anything that has taken root due to my blunder over the last couple of days.

Another consideration is that these bodies were phosphated when new. When bare metalling that is removed. That is why I thought to use Metal Ready which is a phosphating process.

For the exterior I will use a DA sander as used in the body shops to go over each panel then wipe it over with phosphoric which should blacken any corrosion that remains. I will then chase that out with the DA a bit like Milt does with his sand blaster. Repeat until there is no sign of blackening. Then I will spray on the Metal Ready product which I am lead to belive is a phosphating etch primer. I will repeat this for the shell. I am told by the UK agent that primer goes straight on over Metal Ready with no keying or flatting process.

I would be grateful to hear what you think of this.

Thanks again to you all.

Keith.

[Zeke]

Keith, I think you have it down pat. What I found was that rust had migrated from stone chips that went to the metal. Under a small chip would be a much larger area that, as you say, turned when treated. I hand stripped the car and then just detailed the spots with a small portable blaster.

My car had been left for dead, under a tree and with a tarp on it. This was in KY which is wet and humid and then wet and cold. A few years of this took its toll. Having the car under the tarp made things worse, AFIC. It's hard for me to believe, but the car had been completely sandblasted to bare metal on the exterior only and repainted at some point in its life. The primer was epoxy, me thinks. That probably saved the car from total deterioration. One would not have guessed the car was "restored" once before by seeing it when I got it.

After restoring a '44 Jeep, building a 914 race car (those cars are notorious for rust under the battery) and now this 911, I must be some kind of rust expert. Just get rid of it and don't let it come back. Your method sounds good to me.

[FrayAdjacent911]

I got a question... maybe not really related to this topic, but the pictures beg me the question...

Do the fenders just unbolt and come off?

[dtw]

Front? Yes.

[Matt_C]

Yes, the fenders are attached by bolts that run along the side of the hood, and underneath to a fender support that runs perpendicular to the top of the fender.

[FrayAdjacent911]

ahhh...

my 70 911T has a 74+ front passenger side fender... I don't know for sure, but judging on that, and some bondo in places down the passenger side (not too bad, I think), I think someone put it into a wall or sideswiped something.

I found a place where I can get a fender for $550 or so. Eventually, I will be replacing the incorrect fender with a correct one. ... anyone need a 74+ passenger front fender in decent condition??

[carreraplanes]

Milt,

Thanks for your words of comfort. Sleep should come a little easier tonight!!

Keith.