Windscreen surround rust repair

[disco stu]

Hi all. I was hoping to get some advice from you all with some rust around the windscreen on the NL.

I pulled the windscreen out today (your welcome for the rain that brought!). I've found some rust patches that I would like to deal with properly while I'm there. Nothing real deep, so no holes, but it will only spread if not dealt with now. Spread in parts around the whole windscreen

In the photos you can see that its come from outside the urethane line. There is still the line along the edge that is well adhered. My thinking was that seeing there is the well adhered line of urethane I wouldn't have to stress too much with the urethane primer stuff (its dear as poison) and rely on the urethane adhering well to that.

In that case I was figuring that I would be right just bringing it back to bare metal and giving it a coat of paint. Looks aren't a big deal in this area as the trim etc will cover it up, just want to make sure its well sealed and won't rust. I'll just have to make sure no overspray goes on the urethane line there currently to ensure it adheres well

Paint I've got is an epoxy and says it doesn't need primer onto steel, so I was thinking of just whacking this straight over the bare steel once I've ground all the rust down. There will then be some urethane adhering to this paint, but I'm intending the strength will come from the urethane bead already there.

Do you guys think I'm on the right track with this repair?

Would appreciate any other advice you guys might be able to offer

Cheers, Stu

[erad]

In a previous life, I was the Senior Mechanical Engineer with the Snowy Mountains Authority. One of my jobs was maintenance of the turbines, including inside the spiral casings. When installed, they used to use Seachrome Primer, but that was a lead based paint. The modern method is to grit blast to a near white finish (Class 2.5 minimum - Class 3 is a white or surgically clean finish). Then they just sprayed epoxy paints straight on - no primer. This was for the wetted surfaces of the spiral casings. The pipelines all had coal tar epoxy coatings in them and as far as I know (25 years later) they still have not been painted since new. Some of the pipelines are over 70 years old now, and they had coal tar enamel on them. Coal tar epoxy replaced the enamel in later years. Whatever, the paint was thick and sticky, but it worked.

Your case is nowhere near as critical as indie pressure pipelines, so it should work quite well, as long as you get a good thick layer of paint down - maybe 4 or 5 spray coats. Firstly, clean the rusted areas thoroughly - as best you can, using fine emery or glass paper to get a shite and briney finish. The I would start with a thin coating of Zinc Rich epoxy (eg Galmet), followed by at least 3 coats of your epoxy paint. That would give you more than what Mitsubishi did when new.

[gemster]

I would take it all back to bare metal and I mean BARE... No paint, rust or sealer left on....treat the rust, then prep and paint in normal way, using the standard paint for your car... Give the area extra coats if you want...

To do this job properly, allow yourself at least 2-3 days and no moisture or rain... Issues will occur if you rush this job... You don't want to pull your screen again to fix something that you didn't fix before....

No need for 'special' paints, as that's where some can come undone trying to get different paints to adhere to each other...

Gemster...

[disco stu]

Thanks guys. Interesting to hear all that erad. For some reason I thought epoxy paints were a newer thing than that

Part of me is wondering if it's worth all that effort to take it all back Gemster. It's not a special car in any way, and I just want the thing done and registered and things keep dragging on. Obviously can't leave the rust that I'm seeing now, but I figure if I deal with the current rust properly I should get 10 more years out of it. But, and this is where I know I'll probably end up doing it your way, what if there is a bit of rust I'm not seeing and I did end up having to do the windscreen again in a years time.....this is why this stupid car has taken me 12months to get registered!

One thing in wondering is the need for the urethane primer onto the steel/paint if I'm removing that bead of urethane that is currently well adhered. This stuff does say it's primerless, and it normally adheres quite well to most glueable surfaces, so it should be fine, but I'll check the data sheet. Once again, don't want to be doing the screen again in 12 months.

Thanks for the advice so far. Merry Christmas all

[NFT5]

Two pack epoxy primer is just about the best sealer and rust preventative you can get. We use it in the shop whenever bare metal is exposed, prior to painting with high fill primer or topcoats. It's what is used in restorations after grit blasting. Surface needs to be well prepared, scratched to not finer than P180 and clean.


Once coated in epoxy, paint can be applied without further preparation after about 30 minutes and up to a few days. After that it needs to be lightly sanded.


I wouldn't use a 1K epoxy, if that's what you have.

[disco stu]

Awesome, thanks. Yes, it's the 1 pack epoxy enamel that I have. I'm working out of spray cans, don't have access to compressor and spray gun etc. Can you get the 2k primer in a can?

[disco stu]

Just to clarify, I'm aware 2 pack sets from chemical reaction. I was told that you can get the cans there you break a tab or similar and the 2 parts mix. You then use the whole lot within 30 min or whatever and boom it after that time

[disco stu]

Actually, seeing this is where it is I'm thinking I could just brush on 2 pack epoxy paint. Saves some of the hassle of protective gear. The finish doesn't really matter as it's got covers over most/all of it.

Sound reasonable?

[NFT5]

Actually, seeing this is where it is I'm thinking I could just brush on 2 pack epoxy paint. Saves some of the hassle of protective gear. The finish doesn't really matter as it's got covers over most/all of it.

Sound reasonable?

Brushing it on is just fine. A common trick to get in to places that you just can't get the spray to reach.


It's not as dangerous as urethanes containing isocyanates in the hardener, but don't breathe it in if possible.


Your biggest problem will be buying the very small quantity that you need since it usually only comes in 4l tins with 1l hardener. See if you can find a panel shop that will give you maybe 100ml of the epoxy and a little hardener. The one I use mixes 100g epoxy to 18g hardener and 16g thinner but the mixes do vary a bit from brand to brand. Most shops will be closed at the moment though. Pity you weren't a bit closer, I'd give you some.

[disco stu]

That's great, thanks Chris.

You answered my next question-how to get hold of the small amount I'll need. I'm guessing most shops will be closed until about Jan 6, so it's another hurry up and wait situation with this car. There are a few spray painters in my hunting club so I'll ask a few of them

Appreciate the help

[disco stu]

Well the president of the club came around and had a look, got me on the right track. He has to duck back into work on Monday so he will pick me up some 2 pack epoxy primer and some color that is really close that I will just brush on

[NFT5]

Good result.

[disco stu]

Cheers for your help too.

I've ground the rust out, currently getting all the paint and urethane off.

Got some rust appearing further down so I might have to take off the front panels. Also some at the bottom of both pillars which will be visible, so I'm going to have to find some proper matched paint for those spots and put a little more work into them. Great time of year to be trying to find paint!

[disco stu]

Think I've found the cause of the rust. Lots of cut lines through the paint around most of the windscreen. I assumed it my cuts from taking windscreen out, but then I find rust under most of the cuts, plus I was careful not to cut down like that for this very reason. It would appear this is an aftermarket windscreen and whoever took the old one out took the amount of care one has come to expect from "professionals".....hence why I wanted to install this myself

Spent ages going and grinding out all the little bits of rust. Treated it and then found more while sanding the treatment off. Done the best I can, washed it off to make sure there isn't any converter left on there. Ready to clean it and paint once it's dry

[disco stu]

And was hoping to get the top coat on this morning after priming let night so it was still a little green. Car was just way to hot-I couldn't even put my hand on the metal. Will have to do it tomorrow after this southerly comes through, hopefully it still adheres just as well after sanding it