93 body work

[asus]

well, my 93 has a bit of rust on it.. i am going to grind it down to mettle.. take some sheat mettle, use rivets,, sand down the rivets.. and then bondo smoth, and use color matched car paint and clear coat ++ some wax.. is this a good way to fix the rust?? any other suggestions..

[94_Rolla_Guy]

i would pass on the rivets if you grind them down they will fall out, if there aren't rust holes id use bondo and fiberglass just don't prime it and leave it, primer and filler are pourus and will let water to the metal....rust is back...

[ice_d_mugg]

ive always used a method similar.

if the rust is through the metal, like big holes, or the metal is soft where the rust is, depending on where on the car it is, you need to find where the rust ends, and take a cutoff shear, a cutter wheel, plasma cutter, or anything to cut a little bit of the good metal out, to keep any of that "cancer" from ruining what you do.

then, while there is a big hole there, take the time to spray some type of corrosion inhibitor behind the panel, i use kleanstrip's rust converter, it converts it to black primer, then find some type of weldable zinc primer and spray in behind the panel, this should protect whatever you do also.

after this is done, shape your patch metal the way you need it, make it about a half inch to an inch bigger than the hole. spray it also with the weldable zinc primer on the backside and rivet it in, or tack weld it, however you prefer. if you are welding, the optimum wire for MiG is ER70S6, with a .023 tip.

then you may take some type of shortstrand fiberglass reinforced filler, such as bondo's bondoglass, and get a good fill around the edges of the patch. let this dry, and take a grinder with a 36 grit disk and grind it down pretty good, at least flush.

after this step, you may take any type of plastic filler, 3M quick build adhesion i prefer to use. cover your panel as far inward as you need to, and go as far out on the car as you need to in order to make it flush, usually 6 inches, maybe less maybe more, depending on how big the area is and how flat it is. and if you apply extra layers of filler, be sure to recoat the whole thing in filler, if you dont it will show.

when you are sanding, 40 grit paper in long strips on a board sander does great to cut it down to shape, then switching to 80. on a flat panel, ive found to keep the waves out, is to sand downwards from the top at an angle from front to back and vice versa. the right type of sandpaper to use is aluminum oxide, its got a yellow-brown color to it, and it doesnt clog up as easily as other paper.

In order to cut time and headaches with your filler, if you have imperfections like little pits, pinholes, lines, or whatever in your filler, instead of applying more filler, USC makes a great product called icing. you can lay this in a very thin coat, or medium coat over the whole panel if you like, its so thin and light that you can apply it however you need to, but i prefer to coat the whole panel. this must be sanded with 220 grit sandpaper.

The final preparation must be that you coat the area with a primer surfacer. use at least two medium wet coats, three would be great. do not use the rattle can type, ive had bad problems with aggressive paint solvents lifting this stuff like stripper. a good surfacer to use is ppg's mp182, i believe its mp, anyway if you say surfacer and 182, they will know what you want.

for final sanding, use a wet 400-600 grit paper. 400 is quickest to cut, 600 is optimum but takes a while to sand it down. 500 is the middle. you want to sand the area completely smooth, and if you are blending this panel, go ahead and sand the whole panel with 1500. depending on where it is, a whole panel is say, a fender, a whole door, hood, the quarter panel ends where the roof meets it, etc.

omni by ppg makes an economy paint that is cheaply had, and a quick clear coat for spot panel repairs.

to prep the area with paint, use soap and water to wash the area, dry it, then use wax and grease remover on the whole panel, do not touch the area after this, then wipe it down with a tack cloth, you're now ready to paint!

to go about blending this panel, you want to first spray over the primer, pretty lightly, almost a transparent coat and a little beyond the primer. second coat, the same thing but go just a little further. you may repeat this step up to 5 times or however many times it takes to hide.

after the paint is blended, the whole panel must be clear coated. if you cannot clearcoat the whole panel without it having a break in it, per say, for a door, or for some other panel, like what is in the quarter panel sometimes, when you spray up to part of the roof where you finished sanding, a laquer thinner poured into the paint cup after dumping the extra clear out may be "LIGHTLY" sprayed on the edge of it to burn it in. this must be done with a VERY narrow spray fan. clearcoat may be applied in 3 coats. when you are applying the clearcoat, make sure you have no dry spots in your coat, its much simpler to fix a run than a dry spot, be sure to wet the panel, but dont soak it.

let this cure for at least 16 hours before even going near it, if your clumsy like me.
after it cures and you notice a run or other imperfection, wait a couple of days, then, if it is pretty bad, use 1000grit wet to bring it down some, then finish with 1500grit wet, to bring the shine back, buff with rubbing compound and polish it.

DO NOT WAX THIS AREA FOR 90 DAYS OR 3 MONTHS!!!
Solvent is still coming out of the paint and if you create a barrier with wax, it will bubble up and ruin your paintjob.

heres my estimate on materials:
1qt Bondo Bodyfiller $8 at walmart
1 qt Bondo Fiberglass Filler $9 at walmart
24oz tube USC Polyester ICING $20 - optional but VERY worth it!
1pk 40 -->
1pk80-->
1pk 220-->
1pk 4/5/600 --> these are all between 3$ and 6$ a pack
1pk 1000-->
1pk 1500-->
1 tack cloth ~3$
1 qt wax and grease remover ~3$ at walmart
lets say 1qt paint in omni $20, medium reducer 7$ if in 70 degree weather, if lower use slow, if warmer than 80, use fast
1qt of clear, i know omni mc161 urethane clear is 20$ and the catalyst is $16
your choice of rubbing compound and polish.

i really hope this helps you out...took me nearly an hour to type it, but i enjoyed it! im a newly I-CAR certified technician, i work for myself, and bodyshops charge alot, so i like to stick my neck out for everyone.

[tashirosgt]

I enjoyed reading that. Is the metal patch welded all around the edges after it is tacked or is it held in place only by the tack welds and the filler? If I am lucky enough to work on a place where I can either put the patch on the front of the panel or on the back of the panel (so it is slightly recessed from the rest of the body), which is the better choice?

[ice_d_mugg]

For warping purposes, the weld is only tacked. When you are tacking, you should move around the panel, or at least give it time to cool to prevent warpage. This shows really bad in the final finish and its hard to correct.

Recessing is honestly the way to go, if it is a small patch. But only if you have something that can flange the sheet metal around it, for example a punch/flange tool. Or, if you have access to the back of the panel, for instance, a fender, you can remove it and weld it to the backside. Any time you are welding, be sure you restore the corrosion protection, it burns away when you weld. If you are able to do that and recess it, fill it in with the short-strand fiberglass filler and then grind it flush or just a little below the other sheet metal, making sure your tacks are also flush, then fill it over with filler.

But for larger patches or if you cannot get ahold of a punch/flange tool, then tacking it just above the sheet metal is the way to go, its a little more work, but it works out. Body work is 70% sanding and 30% patience.

But also, as a side note, if it is a front fender per say, and it has that 'cancer', new fenders are only about 90 dollars from the dealer with zinc coating already applied.

[Flashmn]

well, my 93 has a bit of rust on it.. i am going to grind it down to mettle.. take some sheat mettle, use rivets,, sand down the rivets.. and then bondo smoth, and use color matched car paint and clear coat ++ some wax.. is this a good way to fix the rust??

No thats a shitty way to do it, sure its gonna last few years, but the rust will be back.

[ice_d_mugg]

hey, give the dude a break, i told him the best way to do it.

his rust really isnt that bad, i have pics of it, he wont even have to make any patches, except for the lip in the fender, and even then he doesnt need the best, its a hard place to attach any type of metal. but i think he will be able to handle it.

Rust is like Cancer, you can treat it, but it will always be there and come back...and it spreads like AIDS.

[Flashmn]

Yeah, well.. you did give good info. But however, ontop of the weld seams I'd use lead and tin it, makes the seam "closed" and it wont rust in the future. Bondo etc are fiborous and they can let moisture in.
I do this stuff for living u know.. ;P

[ice_d_mugg]

i also do this stuff for a living, fiberglass is waterproof. but if the work is covered with primer, paint, and clearcoat, how is water to penetrate? maybe from the backside, but the corrosion protection was to be restored before and after the welding.

[Flashmn]

Well you do it how you want to, I have no intrest on arguing about this.
But if you dont close the seam, this will happen. This is what happens with bullshit bondo repairs.

[ice_d_mugg]

who the hell did that? sounds like it wasnt muleskinned out properly and it sat in primer for some time before it was painted. out of all the repairs ive made, none, and i mean none has come back to bite me in the ass. Fiberglassing over ground welds and seams is the way i was taught, by the I-CAR 2004 teacher of the year, one of the best teachers in the nation by the way.

I feel like arguing this point, because theres a right way and there a wrong way. the wrong way looks good for a while till it bubbles through the paint.

btw, bondo is a brand, not the product. i use almost exclusively 3m premium fillers.

[Flashmn]

who the hell did that? sounds like it wasnt muleskinned out properly and it sat in primer for some time before it was painted

Supposedly the pros in the philippines... The reason that happened was that nobody prepped the seam with stuff that can withstand welding, such as galva-pro...Then ofcourse it started to rust from where the paint burnt away. Wanna know whats the most ironic point on this, its my car..
I generally dont do fiberglassing, I use bodysolder, then smooth that, then if needed use bodyfiller, you wont need alot. Plus the good thing about body solder is that it gets sucked into the smaller holes, which are left after migging, making them air and thus moisture proof, no future rusting.
Then after painting the behind with etching primer, I use dinitrol waxbased rustproofing on the behind side, rustproofing it and making it impervious to rusting. Never had a problem with that way....

the wrong way looks good for a while till it bubbles through the paint.

YUP, Like the shit done on my car :rollseyes:

Yeah I know bondo is a brand, I just call fillers bondo.

[ice_d_mugg]

from where the paint burned away? i thought those phi pros knew you had to grind it back and feather edge it?

ive always used 3m weld through primer, its more of a galvanized coating thats weldable. and all the burn marks from the welding i always muleskinned out before i applied the fiberglass.

but ive never used bodysolder before. but yeah, the self-etching primer is the way to go, on bare metal substrates thats what ive always used prior to applying any surfacer before topcoating, provided thats all i had left to do.

Primer sealer also does a good job of sealing out the old paint and the primers used, it really helps the color holdout too. it seems to help with exterior corrosion protection also.

Ive really really been wanting to buy one of those little spray guns with the long nozzle on it to slide up in tight spaces and in frame holes to apply the corrosion protection.