|11-30-2012 04:55 AM|
Barry has valid points that will serve you well, do one rust repair at a time, for exactly the reasons Barry gave you. Start with the smallest one first, make your repair panel fit properly and weld it in using a stitch method, allow each weld to cool before attempting another one and stagger your welds (weld one spot and than the next one as far away from the first one as possible). This way you will minimize the warping of the metal you are welding. All welds must be closed, by this I mean when you are done welding there shouldn't be any gaps between welds, it should look like one continuous weld. Grind your welds down with a disc, no coarser than 36 grit and 50 grit works also. Rough up the metal around your repair area with your grinding disc and apply your body filler. Block sand your body filler, starting with 40 grit, moving up to 80 grit and finishing with no less than 180 grit before priming. You can guide coat your body work so that when you block it for straightness, your low spots will show and you will be able to apply more filler to the low spots. When you prime, prime and area well beyond the repair area, apply a second coat within the first coat and a third within the second coat allowing each coat to flash before adding another one.
Now you can move onto your next larger rust area. The experience you gained by doing a small area will serve you well when attempting a larger area.
It doesn't really matter if you strip the car first or do rust repair first...I would do rust repair first, especially if you may need to move the car in and out, you don't want to expose the car to the elements considering it would be in bare metal. When you strip a car there are several ways to go about it, you can use 80 grit on a DA (dual action orbital) set on the rotating only mode. If this is the way you plan on going, keep your paper fresh and sharp and keep the orbital moving at all time. If the paper isn't sharp or you spend to much time in one spot with your orbital, it will create heat and it can warp panels. On Hoods, roof's and deck lids I prefer to use a chemical stripper. It's messy, it stinks and it may take several coats to remove the paint. After the first coat is applied let it sit the recommended time and remove what you can with a plastic putty knife and repeat until most of the paint and existing primer is removed. Clean your surface with lacquer thinner or similar product and remove the the left over paint or primer with your DA. I prefer a product I believe is made by Marhyde called "Air Craft Stripper". It's fast, it's efficient, it stinks and it's messy but it does work. When you are done stripping, don't be alarmed....you will find other areas on the car that require body work and or rust repair. Take your time, ask questions and make sure you don't take short cuts and you will have a much better finished product.
I hope this helps and if you need any more help, please ask.
|11-30-2012 03:45 AM|
Unfortunately I have a real job, so have nights and weekends only to work on my cars and my way is what is most efficient for my schedule and I can normally do 2 frame offs a year but in all fairness, only cars I do are C1,2 and 3”s Corvettes or GTO’s, so I know them inside and out.
I have not done a rust repair in 20 or so years but my plan may work for you.
The last GTO, went out one night and cut off left quarter, fitted the new panel so it was ready to weld next night. The next night finished my welds and then the next night moved on to the next panel requiring the most work.
So to answer your question, fix the one quarter rust area and when done do the next, I think the most wasted times, UNLESS you are a body shop is working two-three bad panels at a time as you spend more time running back and forth and chasing tool from one side of car to another.
Corvettes, I do different, first nigh I get car disassembled, so next nigh I can remove body and depending on model I know that will take 3-4 hours.
Hope this helps and not saying my way is best way but my way.
|11-29-2012 08:04 PM|
|novafreek6872||Rust repair first for sure, and then most likely strip the car to the metal. Hard to say without more info. Post some pics of the beast|
|11-29-2012 12:01 PM|
Sorry to be such a newbie, but thanks! Starting the project-what should I tackle first? Should I sand the whole car (grit#?) , should I do the rust repair first? Where would you start? I guess I am struggling with the order of operations, thanks for the help!!!!
|11-18-2012 09:04 AM|
Made a mistake on a statement in my second post, sorry but was in a hurry and once you post you only have a few minutes to correct, that is why writers like me should not be on here.
Clean bumper with “soap and water” (dawn original formula) OR “waterborne wax and grease remover”—Only.
These bumpers are very difficult to work on, well no different really than anything else but the hard part is repairing on that will not bubble.
If you need any help, send me a PM and I will send you my phone number, the PM will go to my email, so will see inside a few hours on most days.
|11-17-2012 07:57 AM|
|Dayo5||Wow! Thanks for the awesome tips. I knew it was not going to be fun, but geez. Thanks again, I will do my best and then post some pix.|
|11-14-2012 12:55 PM|
|tech69||awesome, thanks. I have a word doc with all kinds of goodies pasted and this will be added. Great insight on an often missunderstood piece of hot rod history.|
|11-14-2012 12:42 PM|
I like your videos, helps the guys a lot.
Strip bumper with a 180 DA.
Do the major repairs with the two part Duramix type products.
Clean with soap OR water or waterborne wax and grease remover.
Let set 24-48 hours (very important)
Spray coat of a "flexible epoxy", set set 30 min to 3-4 hours and then spray a couple more coats, let set 24-48 hours and sand with 180 dry, to smooth out.
Use any two part glazing filler at that point for the minor chips.
Sand and coat with 2K primer or epoxy.
Adhesion promoter will be the weakest link, don't use it.
It took me 60 minutes of class time, to go through the steps at the GTO nationals, so this is the short and sweet version.
|11-14-2012 12:27 PM|
on the one I just did recently
we had trouble with even a flexible poly glaze filler sticking to it. We stripped it back off in sections and covered nearly the whole thing with bumper repair. The flexible filler then stuck pretty well on top. In the few areas where the flexible filler was adhered to the endura rubber we sprayed SEM adhesion promotor, and not sure if it's solvent base. So as far as materials used we were in the dark. I gathered what info I could find on-line but it was nothing compared to the insight Barry is letting us in on right now. Wish I read this post BEFORE we fixed it, and it makes total sense about creating a barrier coat. I just didn't have a good feeling about ANY polyester flexible filler adhering to the endura rubber no matter how good it feathered out after adhesion promoter was applied. I just didn't know better at the time.
Anyhow, I did make a video on the repair and if anything it can be helpful in addressing fitment issues, as it seemed to be a headache making it fit right.
|11-14-2012 11:47 AM|
Also, it must be stripped.
Also NO polyester should ever come in contact with the bumper itself or it will bubble, only a matter of when.
Only thing that touches the bumper is a two part plastic repair for the bad spots, like Duramix 4036, 4040, 4030, Sem, 3M or other like products.
Any paint rep that says treat like any urethane bumper, most likely has no clue what one is.
All polyester is only to be used over epoxy as a barrier-coat.
Use no solvent borne cleaner or adhesion promoter.
|11-13-2012 05:30 PM|
|novafreek6872||LOVE the 70 GTO nose... just had to say. Its my favorite year. I knew a kid in HS who had a 70 in awesome shape...he paid $1800 for the thing!!! may have been a Judge...I dont remember...ah, the good ol days...|
|11-13-2012 01:36 PM|
1970 GTO Nose/Front End
I am getting ready to start prepping the body for paint, as you can see from my profile pic, the nose is in good shape, but weathered. Should I spray it with primer filler and see what it looks like? Or should I try to use filler to smooth it out first? Thank for your inputs!