I recently decided to take off paint from car since it was chipping. The car has a lot of areas wear the mud or bondo lifted off car. My question is would I just fill in the open areas and blend in or scrape off a of the mud and redo. What would be best to work with. Any tips or advice greatly appreciated. I don't know if i bit more than i can chew but it's been like that for a couple year and as Time goes by the chips get bigger

 

Bump

 

The repair separated for a reason. You are going to have to strip the car down to bare panels unless you want the same thing to happen all over again. There are pros that will help you out with more information.

 

Photo's of any area that has or had the BONDO will need to be posted. I can not tell you what to do unless you make it so I can see what you are seeing.

The bondo that peeled off...what is under it???? Paint/primer or bare SMC???

DUB

 

Here are pics. The back and doors is fiberglass the Front fenders seems to have a thin layer left on top of it so fibers doesn't show.

Thanks

 

The back has some primer sprayed on it but the rest is bare

 

from what it looks like the whole car or most of it was skinned with filler. If that is the case I would try to take it all off. The thickness of the filler is what makes it fail so easy. on an area that needs more filler use a fiberglass filler. this has fiberglass strands in and gives it much more strength. I think the rule of thumb is body filler should not be used more then a 1/8 inch thick.

as far as getting the old stuff off get out a 36 grit paper on angel grinder and about a full day of dust. sorry for bad news

 

Thanks for the photo's. But like at a sunset out west...there can be times where you do not know where the mountains stop and the sunset clouds begin beacsue they 'blend' in so well.

It is hard to read the depth and which layer is actually the bottom.

In your third photo...the one with the drivers door handle showing...there is a dark spot to the right of the handle. Is that a spot where you got down to a red oxide primer???

If what you are scraping off is a light gray hard material....it might be a polyester primer.

If you can...take some 80 grit and carefully sand down a small area until you reach the bare SMC....and then feather it back so I (we) can see how many layers you have on the car.

Depending on what you have on the car...I would wait.... because if you take a grinder to your body with 36 grit on it...it might be a bit too aggressive when a less aggressive grit sand paper will do the job without removing too much body material thickness.

Also...not knowing your skill level...going at it with a rough sandpaper with a power tool can be catastrophic. Not writing that you cant....but writing that I have repaired my fair share of Corvettes when 'someone' got a hold of it with a power tool and did so much damage due to not knowing what to do and how to do it. Thats all.

**** MY OPINION****
Also. Not meaning to **** anyone off. My philosophy is that if your need to add so much filler...that you actually entertain the use of a filler with fiberglass strands in it. Then the repair should be laminated with matt and resin so if proper techniques are employed...you reduce the chance of air in the repair which can come back and haunt you...or the use of a filler than can actually handle being applied thick and holding up. I know that the 'rule of thumb' is no more than 1/8" of filler...but in reality...that is unrealistic. With the adhesive/filler I use and my techniques...I can easily triple the 'rule of thumb' variable without any failure. Using a filler with long strands of fiberglass in it makes it really hard to mix thoroughly and make sure that you are getting all the air out...which is almost impossible unless you vacuum bag it. It is up to the person mixing and applying a long, short or chopped fiberglass strand filler. If when grinding it after it was applied...if you find a lot of air bubbles...it was not mixed and applied correctly and you are asking for trouble...in MY opinion. Which is why I use these types of fiberglass strand fillers ONLY in when repairing something that I am going to pull a mold off of and I do not care if it lasts. These types of fillers are an easy way out and made for convenience...versus lamination. They have a but are not something that I use as a repair material. But that is just me.

 

While I was going through the body I found multiple cracks throughout body from the mud I guess the not much for salvaging something that's gonna keep cracking. The more I look the more I find. What would be the best way to remove for a noob and what mud or filler works best with fiberglass.
Thanks

 

I have removed filler on panels much like what you have with an inspection sticker razor knife. Get the razor under the filler and pop it off. You might get some of it that way...but you will more than likely run into areas where the filer is stuck really good and the razor blade will stop. Using a heat gun can help in some scenarios.

I use a grinder with 36 grit and I have different size pads. 8", 5", 3"and a modified holder for a 1" disc. The different size pads allow them to be used in specific areas. SO the 3" disc will get into tight curves without too much damage if you are careful and WATCHING what you are doing. The 5" in areas that are a larger curve in the body and the 8" the same way. I use the 8" on flat surfaces...such as the top of the hood and rear deck by the fuel door, below the feature line in the doors, areas of the top hood surround where they are flat...and also quarter panels and fenders...but that is beacsue I know how to move the sander when grinding.

With you being a novice in body work...do not worry. JUST REMEMBER...when you got your drivers license...and began to drive...you HOPEFULLY did not drive around with your foot to the floor ALL the time. Well...using grinder and sanders it is much the same. JUST BECAUSE they put a trigger on the tool that will allow it to run it at full power and RPM....DOES NOT mean that you HAVE TO use it that way. Being watchful of the speed and rotation of your tool and the amount of pressure you are applying on the panel is what counts. I always prefer to use a sander/grinder at a slow speed so it does not get away from me...and it also can make the sandpaper last longer because I am not heating it up. I also TRY to have the rotation of my disc/sandpaper going in a direction so that when I am grinding....what I am grinding is being directed to the floor...instead of up in the air making a cloudy work environment. In many processes..I have my shop vacuum tube set up by me so I can suck out the dust and whatever right away. I can hold the vacuum tube with one and and grind with the other when using the smaller grinders that I have that are easy to hold. Sometimes thinking ahead and taking the time to engineer something that will help you in not having a thick cloud of dust is worth it. TRUST ME....I have been doing this for long, long time and small things such as a vacuum keeping things as clean as possible will pay off. I know...sometimes it is what it is...but having a 1/2' of crap on the floor is somersetting I do not tolerate very well at all.

If you plan on grinding this stuff off. Keep a watchful eye on it and try at all cost to not grind heavily into the body. ESPECIALLY at the tops of feature lines SO...even if you leave a little bit on the panel so you can come back with a long board or a finish sander and get the rest off might be the best.

Whatever you do...do NOT freak out or get discouraged.

And any bit of advice I can give you. DO NOT look at your car as a whole when grinding. STOP...and FOCUS ON ONE PANEL....and forget about all the other stuff. By focusing on the panel you choose to work on for that day...if you do get it sanded and completed at the end of that day...you will have ONE panel down. Then pick another panel and do the same. IF...you jump around on the car and work all day on it until you are dragging your backside in your house to go to sleep.... and when you look back at it and NOTHING has been COMPLETED...that is when you might feel overwhelmed.

Also...not knowing where you are doing this or any of that. Make sure that the clothes you are wearing get put in a plastic bag and you do not go in and sit down on your couch...thus NOT brought into the house. The dusts that come off Corvettes when doing this type of work are really bad and you do not want to contaminate the environment of your living space. If you can handle it...wearing a Tyvek paint suit and all appropriate dust masks, goggles, face shields, gloves, booties for your shoes and even a respirator.

DUB

 

Thanks alot I'm working on car in backyard I will keep all this in mind as I only really work on car on weekends when I'm free and new to the hobby. I feel good working on car as it makes me feel better about changing stuff or working on it even if it takes me 2 days on a 30 min job. Thanks for the help.

 

I REALLY HOPE that you have the car protected. Allowing it to get rain on it when you have it stripped is not a food idea at all. And covering it in plastic is EVEN WORSE.

If you car is out in the environment...you really need to be careful and possibly re-think 'things'...or find a spot somewhere inside to do this.

DUB

 

DUB, what is going to happen if it gets rained on? I only ask because I recently (last week) stripped my rear clip and it is raining as I type this.

 

Its not just the rain that you should be worried about when you put a Vette with bare panels outside. Outside, Those bare panels are very porous and susceptible to all kinds of contaminants that can come back to haunt you you later. Even a sweaty palm placed on bare glass can case you adhesion problems if your not careful.

 

That is good to know thanks that means I have to clean out garage and hit it hard.

 

100%.

And just because you have it in a garage...if that garage is a hot box and holds moisture much like a green house...you are actually doing more damage to the car as a whole than you can imagine. This is why covering it in plastic or even a car cover is the beginning of the end if you do this regularly.

if you do not believe me...then keep doing it and wait for the tiny blisters and bubbles to show up one day...and then wonder why.

DUB

 

Also I forgot to add, Do not use prep sol on your bare glass. I have always preferred to use acetone to clean bare glass. Especially before applying anything to bare glass. Filler, resin, primer, Anything. Keep us posted.