What is the best way to clean an area that is contaminated with oil? I sprayed epoxy this past weekend and have a couple of spots that have something on the smc. I washed the area to be epoxied twice with dawn and let dry, cleaned with waterborne wax and grease remove the night before shooting and still have about 4 small places that evidently have grease or oil on them.

 

Where are your OIL spots?
"DUB"

 

They are in an area on the front drivers side fender behind the front tire. It seems to be where the holes are for the stingray emblem and at the vent behind the front tire.

 

What year is you Corvette? 1973-1976? and can you show a picture...without epoxy on it to show the stains. Also just for information sake...look on the inside of the panel where these stains are located and see if you can spot any foreign substance on the inside of the panel.
Is the epoxy reacting to these "stains" to the point that it is not curing and staying wet or remaining glossy when the other areas are dulling out.?
"DUB"

 

I just got finished sanding these areas back down to the bare smc (75 model). The epoxy primer was dry but had fisheyed. I am going to try cleaning the area again and see if anything is trying to bleed thru. I will try to get some pics posted later this weekend. Thanks for your help.

 

Sanded down the areas that the epoxy spread on and cleaned with dawn and water, let dry and cleaned with waterborne wax and grease remover, shot another coat of epoxy and it ran again. Do I need to use a solvent wax and grease remover or lacquer thinner and then wash and let dry?

 

Waterborn wax and grease remover is best used for raw urethane bumpers and plastic parts where solvent based wax and grease removers can cause adhesion issues. NOT on SMC/fiberglass

I really have a problem with using any type of soap on fiberglass/SMC. IT will absorb into the panel and possible cause for other problems due to not being able to get it out. I use solvents. Such as acetone, lacquer thinner, and even 3M adhesive remover. Each has their uses and depends on the circumstances in which one I use. Wipe on with one lint free wiper..and remove with another CLEAN lint free wiper...and not just smear it around until it dries by using one wiper. All you are doing is speading the oil around and not removing it. Then use ANOTHER CLEAN wiper and do it again. DO not re-use the wipers...they will re-apply what you have removed. And maybe again and again and so on.

You can apply heat with a heat gun...but be careful not to get it way to hot. But yet hot enough to see if the oil will "sweat out" and be removed with the solvent when it cools. If you start seeing dark gray spots...that is the oil being drawn to the heat source. If you have no dark gray spots...then the panel is not saturated enough to cause this issue. Next paragraph explains further...

You did not respond to my earlier post and check the inside of the fender. This is important. Until you identify the source or cause of the problem...you will still have a problem...maybe not at the time of spraying ...but in the future when the oil causes your paint to bubble.

Were the emblem holes filled in and this is the area of the fisheyes? Could be contaminated filler and may need to be removed and replaced with fresh filler.

When you are prepping for epoxy primer...is the panel showing signs of discoloration? Like a darker gray color? Or is it staying all the same color....light gray.

If this presists...and seeing how I have no good photo's to look at...I would grind down the problem area and apply a decent coat of Fiberglass/Evercoat Vette Panel adhesive and then sand it so the primer can be applied.

If you insist on using a wax and grease remover....which I do not on bare fiberglass/SMC....because if the body is rough...and the outer layer of SMC has been sanded on...even with 320 grit...and the structure of teh SMC is now "open" due to this sanding....I consider this ROUGH....and the wax and grease remover will leave behind deposits that you can not wipe off due to it being absorbed into the body. IF you choose to do so...you MUST let it dry WELL so you are not trapping any foreign material in the structure of the finerglass. We are dealing wil a contaminant on the microscopic level here.... or at least I am assuming so due to needing very good photo's to better aid me in helping you.

"DUB"

 

Well I thought I had this problem solved but as you can see from the pictures, the spot is returning. I can not see what is behind it as it is next to the cowl/firewall area. I don't know what I should do at this point as it has a couple of coats of epoxy primer over the bare smc and then a few coat of 2k on top of that. I just don't want to end up with paint bubbling once I get the bc/cc on it. What is my best option for this problem? If I need to strip the area back down and lay in some new glass I will but what will keep it from occuring again?

 

DID you try to apply heat and see if it would "sweat " out some of the "oil"?

From my last post til your last post...what did you try to do to correct this? You did not mention any of your repair procedures IN DETAIL....other than applying more epoxy and 2K primer.

From your photo's. I would grind and apply epoxy resin and matt. Making sure that you grind enough to get to good SMC that is not contaminated. BUT without imput from you on the options of solvents and other processes you can try...it is hard to say anything unless you keep us informed. I am unable to advise you further unless I know what you have done....if anything. I have numerous ways of repairing this problem...racing around in my head...but they are useless...if one..if not all... of the earlier mentioned ideas has not been tried.
"DUB"

 

Judging from the photos you have other surface issues which more primer won't cure anyway. I would remove back down to bare SMC after somehow marking not only the bleed through, but the pits/chips as well, then grind/fill the bleed area with SMC resin/matt, and fill the pits with resin or filler, sanding to level before the next coat of epoxy. Removing an area twice the size of the bleed down to paper thin then rebuilding, leveling and redrilling might do the trick.

 

I have let the car sit in the sun for several days and then cleaned daily as the bleed thru showed. I have not tried to grind out the area and this spot was not visible until I stripped body down to the bare glass. There was no bubbling of the old paint in this area. I can not figure out what is on the backside as I have no way to get back there.

If I grind the area out and lay new matt and resin, how can I lay it on the backside of the panel and build outward to the surface?