1986v6

Well this is my first post here and it is a question. In the rear drivers side footwell there is a small hole in the front leftside corner where the P.O. bottomed out and the undercoating was knocked off it then rusted through about the size of a quarter, my question is what is going to be the easiest most cost effective way to temporarily fix this as the body work on my camaro is going to be last as I need new fenders and a small amount of patch work on the passenger rear wheel well. Would it be possible to cut out around the affected area which would make about a playing card sized hole and replace that section with a patch panel and some of that panel adheisive they use to attach body panels in newer cars its almost like a liquid weld. is this a major load bearing point or would it be no bigdeal as its in the backseat and nobody sits there any way??

JamesC

iTrader: (5)

I used POR-15 products to repair a section of rust considerably larger than quarter size. After several years, all well. Recommended.

JamesC

katiejay2011

You said you used POR-15 products to fix small hole. Which product in particular? i have just been introduced to POR-15 being pain over rust--to stop rust from spreading on and to prevent future rust from forming on bare metal. thanks

JamesC

iTrader: (5)

Mesh and two-part putty.

JamesC

katiejay2011

would this work on fenders as well?? What would the benefit of using this instead of fibreglass be? thanks

JamesC

iTrader: (5)

Sorry, katiejay, I'm not a body man. Perhaps someone with experience will chime in here--or you can start a new thread, which might be to your advantage.

JamesC

Maverick H1L

iTrader: (8)

About how big was the hole you patched? I don't know if I'm ever going to get the welder working (house electrical problems, not the brand new welder itself), and I have holes that are a few inches long (but not very wide)...

JamesC

iTrader: (5)

I'd say it was 2" x 6".

JamesC

Maverick H1L

iTrader: (8)

About the same size as mine, then. I assume the patches are still holding fine?

JamesC

iTrader: (5)

Like the day I finished--and that was several years ago.

JamesC

GWW

Ok this is my attempt to bore the hell out of you. If you want to know how the body shops I have worked at repair rust read on. A fiberglass patch will not work long term. The idea to fix cancerous rust areas is to cut the rust out and replace with new steel. If you have rust in a quarter panel you need to remove the outer section of quarter panel that is rusted and then inspect and clean rust on the inner quarter panel. It will be there. If you do not do this, the rust will grow from the inner to the outer again and quite quickly. With the floor chances are you have more rust than just the little hole. I say that because if you have had enough corrosion to rot a quarter panel or small hole you have more rust damage than you think. Not to scare you it's just something you need to understand and look for. If you patch with fiberglass the remaining rust will lift the glass off or crawl out from under it and create bubbles around it. Fiberglass is a temporary fix and from my experience quality body shops would not nor ever allow that sort of repair. You can have a auto recycler remove a quarter panel from a donor car. You will get the inner panel too and you can ask for a section of floor, a decent sized one. You may be able to buy patch panels online. I would first clean all of the under coating etc from around the hole to see how bad the rust is on the floor. You will also remove a section of quarter panel and examine inside as well. Check around the seams of the rest of the Q panel too. It might be best to remove the entire panel in order to clean up everything. Sometimes doing that in the long run is easier to do and makes a better looking repair from the inside. Look for bubble etc to determine this. My approach is to make the repair permanent. Its not as much work as it sounds providing you have an air compressor and access to a few basic air tools.

1) Clean an area of the floor top and bottom with a small flat grinder, propane torch to remove undercoat, and a die grinder with a roloc disc and a 3M fibrous paint strip disc.
2) Using your die grinder and a thin cutting disc cut out an area of the quarter panel large enough to remove the entire rust area and at least two inches back from the rust. More if you need to make more room to access the patch from behind. Make sure you look for rust bubbles all around the quarter panel, window area, and rocker panel. Make sure the piece you cut out is easy to access with your hands during the patch process. A nice square/rectangular area is best. You may want to remove a lot more. You may want to remove the entire panel. Depends on the situation. Do the same thing to the floor.
3) Using your fiber disc with the die grinder clean all rust off of the inner panel and area you will weld to. Welders don't like rust or paint etc. Clean metal is the key.
4) If you have holes to patch, cut out a piece from your new steel about a 3/8" larger on every side than the hole on your car. The best practice is to use an air flange tool. Flange the body of your car inward. Your patch should rest on top of the car body steel flanged area or overlap onto an existing body seam. Do the same with the floor. If you do not have an air tool you can butt weld/stitch weld as well. I think that method may be prone to cracking over time though since you have to grind your welds so thin.
5) At this point if your inner panel is clean, sand the area with 180 or 240 grit and spray the bare metal with a metal etch zinc chromate primer from a spray can. Keep it off the area you will weld to. There are weld through primers for your welding areas but unless you spray them very thin the welding is very poor because of the paint. If you spray the flange or factory seam area with the weld through primer keep it very thin. I.E. you can just see through it. I never used it during my career and never had anything come back rusting again. I use it now though.
6) Once the chromate primer has dried on your inner quarter panel spray the area with a catalized primer and then top coat with a spray can of factory color. The local paint supplier here can provide me spray cans of the exact color. Yours may do the same. Dupli Color will have it but it won't match very well. You can also buy regular auto paint and spray it if you have a spray gun. High quality auto paint is expensive! Again keep all of this off of your weld area. Undercoat will work too.
7) Clean the area to bare metal on your new panels where they will be welded.
8) If you flanged the car body, welding is easy along the seam. Tack weld your replacement panels in. Start at one spot go opposite corners then in the middle work your way around the patch from side to side. The idea is not to weld so much in one area so to prevent warping. During this welding process use a body hammer and dollies to keep the panels or patch in alignment. With butt welding do the same thing. Have a wet rag handy. Hold it next to your welding while you weld. The heat will transfer to the rag instead of warping your panels. Keep the welds small and slowly stitch things up. Take your time. Excessive warping requires a lot of work to repair with filler. If you do your work right an 1/8 +or - a little bit" of filler max in the worst areas should do it. Always try to minimize the thickness of filler by doing good metal work.
9) Once done welding, grind your welds smooth again don't stay in one area long.
10) Your quarter panel patch should have no gaps in the welding seems. The floor is best to do the same. If you do leave gaps in the floor seam you can buy a tube of seam sealer to seal things up. You're going to need it anyway.
11) Clean up all welding spatter, paint least 12" back from your quarter panel work and thourougly within your weld. You don't need to sand way back on your floor area unless your doing high end restoration type work.
12) Do your plastic filler work, sand it all smooth, feather sand the paint area back so far that you cannot feel a paint edge. Feather your filler out so that you do not feel a filler edge. Seam seal all factory edges that you have used to patch to. Prime with a catalyzed primer with capabilities to apply directly over bare metal. This kind of primer is water tight. Regular old school lacquer primer is not. If you drive the car with old school primer water will absorb and rust will start. Been there done that and had to start all over with the filler prep and priming.
13) Inside your fender well seam seal the lip and prime and then paint and undercoat the area.
14) On the outside you will not use seam sealer unless you have removed the quarter panel completely and have panel joints to seal.
15) Spray all of your work with the primer that can stick to bare metal and guide coat, (a darker color than your primer just misted on) and block sand, reprime and repeat until no high or low spots appear after guide coat and sanding. Once done everything should be your primer color and look and feel dead smooth. You can wipe the panel with a damp rag to show inperfections, remove dust from pin holes etc if needed. If you are new to body repair a trick I learned when I was first starting was to use a dry soft rag, place it in your hand and softly slide it over your repair area in all directions. I don't know how this works but if you are just learning how to "feel a repair" the rag amplifies the waves so that you can tell where they are. The guide coat should do it though for you. High spots will have metal or filler show through the primer. Low spots will leave the guide coat. Once a metal high spot appears stop. You may need to just reprime and guide coat sand again. If the high spot is severe you may have to tap it down and fill it again. The better your prep work the better your paint will look. The primer will continue to sand down but the primer and filler are not of the same hardness so be carefull to keep things even. Use sharp sand paper and a 8" or 16" sanding block minimum. I use the 16" the most for my work. There are longer ones than that too.
16) Have a friend paint it or do it yourself. You've done the hard part so why not do the fun part.

Sounds like a lot of work the floor patch is easy the quarter panel a little more complex but still easy to do just requires a more quality and time. I may have missed something small, drilling out spot welds for instance, but this is the general idea. This may sound like an insane amount of work but in reality it is not that hard to do and this is how all of the quality body shops I worked at would require the patch repair to be performed I was in that field for nearly 15 years before going back to school to get an engineering degree. A complete quarter panel replacement along with your floor other than prep and paint can be done in one day. A patch in much less. It is dependent on tools and the size of patch.

You may want to get the correct tools and fix it yourself at home or perhaps a better choice for you would be to find a community college with a body shop program and make the car your school project. That's what I did with my first attempt at body repair back when the dinosaurs ruled the earth. They even let me perform customers of my own paint jobs and body work in the school facility. Actually was a cool way to meet girls. Pretty ones do wreck their cars. All the tools will be there and you can go ahead and fix the rest of your car and paint it too! You will also get a discount on paint and material. Like I said paint is EXPENSIVE. My IROC cost me 4 grand in the best Dupont paint I could get. $400 per quart, $300 dollars per gallon of clear. Then you have activators etc. A school is a good idea. It also will give you a trade that pays fairly well. Nasons paint is much cheaper than Dupont and works very well. It's just a little off when it comes to stock color matching though.

Sorry for the length but this is how I fixed rust in my body shop career and why rust repair done right is expensive. Hope you don't mind. My fingers are tired. You can PM me if you have more questions or post them here. I can try to answer them on this forum if possible.
Jerry

Maverick H1L

iTrader: (8)

Well, I'll tell you, good luck finding a patch panel from NEW steel for the portion of the floor pan that is directly over the front end of the rear subframe that I have to replace. Replacement pans only go up to the hump that forms the back seat support, and that particular 6x6" hole is a couple inches back from that. Right now, I'll take ANY way I can get to fix that hole (talked to several people on here about it and still haven't heard anything as to whom has actually cut it yet). I have patches cut for the rest but no working welder . Don't mention a junkyard either as most of the J/Y cars I've seen around here have been sitting forever and a day and the pans are all rotted out as a result, especially if the car has/had T-tops.