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Panel replacement

Posted: July 24th, 2011, 1:15 pm
by mitmaks
So I had a customer with some body damage on her car. I decided to share this with you guys, this way you will know what it takes to do job properly. Maybe someone can use this in future as a guide to do similar process on their car.

This was a hit right in the corner of quarter panel.
I went to junk yard and sourced quarter panel, taillight, bumper cover and mirror.
It's very important to cut patch panel right the first time, you can't weld additional metal on it once it's cut off. Start out by drilling out all the spot welds. Once you remove damaged section the underlying metal can be straightened with rubber mallet.
You want to cut patch panel slightly bigger cause it will overlap over the edge of existing panel that you will be welding onto.
You want to double and triple check all the gaps by installing donor parts (ie bumper cover, tail light, decklid to quarter panel gap.
Once you're happy with gaps you want to tack quarter panel in a few spots so it won't move out of alignment. :welder:
You want to protect glass/interior from sparks. A cheap fiberglass blanket works well but be careful of fiberglass splinters :crying:
After all of the welding is complete I grind it down, you want to cool off panel and weld on lowest heat setting, you want to minimize panel warping.
After all welds are ground down I put body filler and sand it down. Next coat of body filler is applied slightly farther and so on.
Once body filler work is done I mask entire car (it's important to do so, overspray travels everywhere and you sure don't want to try to clean it off of entire car.)
You can buy masking plastic from body shop supply store at $5 and it will cover entire car.
I use 2K high build primer and lay on 3-4 full wet coats. It's best to let it dry overnight, it sands much better once it dries
thoroughly.
You might find imperfections while sanding primer ie little pinholes or slight low spots etc. I use Glazing putty, it goes over primer and dries fast/sands easy. Afterwards I'll put another couple coats of 2K high build primer over entire panel.
It is important to use sanding blocks, not your hand. Especially on body lines (this car has plenty of them)
I finish sand primer with 600 wet.
After primer work is complete I take car outside and thoroughly wash it, you want to remove as much dirt/dust from car as you don't want it in the air once you start painting. Next step is masking. I throw plastic bag over entire car except for panel that I will be painting. You want to use 12" or more masking paper around your area to be painted. Reason is, paint and clear coat overspray sticks to paper not the plastic bag. You don't want dry overspray landing into your fresh paint as you're making a pass with your gun, that air will lift overspray from plastic but not from paper.
They make "blending agent" for paint (base coat) and blending solvent for clear coat. For each coat you simply step out father onto the panel you're blending into, this way you won't see blend edge. If done properly you won't see difference at all.
This is where higher end paint makes all the difference. A pint of this paint was $120 but well worth it in the end as it matched car color perfectly. For the clear coat I went with cheper clear $22/quart+8oz can of hardener $16.
After this paint job dried overnight I buffed it with my Meguiar's kit, detailed car and started assembling it.
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Re: Panel replacement

Posted: July 24th, 2011, 4:16 pm
by Calg_93GS
nicely done, cant even see the seam. :2thumbsup:

Re: Panel replacement

Posted: July 24th, 2011, 4:29 pm
by mitmaks
Calg_93GS wrote:nicely done, cant even see the seam. :2thumbsup:
You should not, if you do bodywork properly.

Re: Panel replacement

Posted: July 24th, 2011, 6:59 pm
by Daninski
This is an important step I didn't know about, thanks. Quote, You want to use 12" or more masking paper around your area to be painted. Reason is, paint and clear coat overspray sticks to paper not the plastic bag. You don't want dry overspray landing into your fresh paint as you're making a pass with your gun, that air will lift overspray from plastic but not from paper. unquote.

Re: Panel replacement

Posted: July 24th, 2011, 7:10 pm
by Calg_93GS
mitmaks wrote:
Calg_93GS wrote:nicely done, cant even see the seam. :2thumbsup:
You should not, if you do bodywork properly.
would not believe how often i see "bark yard" body work done and the seams stick out like a sore thumb, or uneven/wave panels from not using a block during sanding

Re: Panel replacement

Posted: July 24th, 2011, 7:49 pm
by mitmaks
You can't see it real good in picture but I made flange on the existing panel so that patch panel overlaps over it by about 1/2 inch
This is tool that does flange and also punches holes if you're doing plug weld
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I've used offset lap weld on this panel. After welding both panels are fairly even to each other ------- ---------- I just have to concentrate weld to weld them together, and there's no burn through as part of existing panel acts as a backing panel for the weld.
You should use least amount of heat possible or you will create more work for yourself when you warp it. Key here is to use lowest heat setting and cooling off area after each weld.
And yes, you must use long block to make sure you're sanding body filler straight and your body work is straight.

Re: Panel replacement

Posted: July 25th, 2011, 2:26 am
by _-Night-Shade-_
You're an artist :2thumbsup:

Re: Panel replacement

Posted: July 25th, 2011, 3:35 pm
by Daninski
Oh man I could of fixed that with a quart of bondo and a big hammer. Just drill some holes and keep building up the layers until your flush (hella flush that is :D ) Then refinish the area with a rattle can of high quality Tremclad, a little buffing and you just scammed the customer out of their hard earned money. Isn't that how it's done. I tell ya, if your into the fixin stuff right and giving value for dollar your a bloody dinosaur. Like they say, do unto others then take a holiday down south. :wink:

Umm, can you do my car next. :oops:

Re: Panel replacement

Posted: July 25th, 2011, 3:36 pm
by Daninski
Whats your opinion on the trend to glue rather than weld panels?

Re: Panel replacement

Posted: July 25th, 2011, 7:08 pm
by mitmaks
Daninski wrote:Whats your opinion on the trend to glue rather than weld panels?
I heard good things about it, personally haven't tried it. Supposedly it's pretty strong. Of course there's no panel warpage, but all you have to do is just be careful not to overheat panel. I have a nice welder that I bought just for this purpose so I'm set with welder. I know it's not coming off.

Re: Panel replacement

Posted: July 26th, 2011, 10:04 am
by MrMazda92
Daninski wrote:Oh man I could of fixed that with a quart of bondo and a big hammer. Just drill some holes and keep building up the layers until your flush (hella flush that is :D ) Then refinish the area with a rattle can of high quality Tremclad, a little buffing and you just scammed the customer out of their hard earned money. Isn't that how it's done. I tell ya, if your into the fixin stuff right and giving value for dollar your a bloody dinosaur. Like they say, do unto others then take a holiday down south. :wink:

Umm, can you do my car next. :oops:

:lol: Wow, just wow!

Re: Panel replacement

Posted: July 26th, 2011, 11:01 am
by cWs306
uhhh. has anyone noticed the Charger infront of the impala? :O !!!!! is that a 69?

Re: Panel replacement

Posted: July 26th, 2011, 7:43 pm
by mitmaks
cWs306 wrote:uhhh. has anyone noticed the Charger infront of the impala? :O !!!!! is that a 69?
That's my 68 R/T

Re: Panel replacement

Posted: July 26th, 2011, 7:47 pm
by wytbishop
Can you describe your welding, grinding, shaping procedure.

Re: Panel replacement

Posted: July 26th, 2011, 8:30 pm
by mitmaks
wytbishop wrote:Can you describe your welding, grinding, shaping procedure.
It's like an art lol. Honestly you have to do a lot of this to have it perfect. Key steps is not to over heat metal, especially this super thin metal that comes on todays cars. I will tack a spot, move to stop on the opposite end, cool each weld with air. On the sides I've just used holes from factory spot welds. The seam I've welded with 1/4 inch long stitch welds. On the inside seam I've used seam sealer to block out moisture/dirt. When grinding weld I grind it slightly below both panels, any low spots will be filled with body filler. You don't want your body filler on thick.
Body filler I do a few coats, it's impossible to get it straight within 1st coat especially with dent this large. This car has some complicated body lines, they don't show good in pictures but you have to pay attention how they go before you begin bodywork. It's important your bodylines are straight and match each other (both sides of car).
I use guide coat in a rattle can, it shows you where your low/high spots are as you're sanding bondo/primer....
I have a variety of blocks sizes/shapes to match contour of the body panel.

I didn't know there would be interest in this thread or I would've taken more pics, sorry guys. Besides customer was waiting on me.
I'm sure I'll post more threads as times goes on. I have a ton of pictures I took of my Charger bodywork. I've replaced various panels on it along with bodywork.
Feel free to ask any questions/comment and I'll try my best to answer all of your guy's questions.