brake fluid damage on epoxy

J

jbon64

i mocked up everything on my epoxy primed frame ,and in several spots i had leaky brake fluid . one spot the epoxy bubbled up pretty good. my plan is to remove the bubbled up area down to bare metal then recoat with epoxy. how should i go about removing the damage ? i would hate to sand it and take the chance of grinding small amounts of brake fluid into the frame then have lifting problems later. what should i use as a cleaner during and after repair ?
 
Clean with 700.
Smooth out with 180, clean twice with 700, and a spot in.
Dot3 does not touch spi epoxy unless real fresh?????
Not cured for 90 days but i have soaked the epoxy 2 weeks old in a bucket of dot3 for months???
 
I did have a brake line leak at my master cylinder. It was dripping on my LH frame rail for an unknown period of time before I saw it. It certainly was a pleasant surprise when I found it had not damaged the black epoxy on the frame.

John
 
This may be another brand, and I don't mind helping but just want to make sure.
 
This happened to me a week ago. I had a bad fluid leak around the master/proportional valve. It sprayed fluid on the bottom of my hood, cowl, firewall and fender apron. My car has SPI black epoxy on everything under the hood but epoxy topcoated with PPG high build primer on the rest of the car. I had a bucket of water and rags handy so I immediately washed everything off and then washed again with SPI WGR. I thought it would stain the high build but nothing yet. The black epoxy still looks untouched by the incident.
 
barry , i used SPI epoxy . i'm not blaming or questioning the product in any way, form or fashion. i had several leaks thru out my system but only had the bubbling in one spot. i used a thru frame fitting and i think it seeped where i drilled thru the frame and maybe soaked in at the exposed metal and worked its way in somehow. the frame had plenty of cure time (well over a year) . i'll go with your suggestion , i just dont want it come back to haunt me when i put color on the frame. thanks for the input !!!
 
Thank you, not knowing was killing me.

I know what happened to you since it only reacted in one spot.
When I test, I spray two coats on a 4x11 panel laying flat on a 55-gallon drum.
When I dip the panel in dot3, it never attacks the epoxy but will creep under the epoxy where I did not have the edges covered.
Usually starts to show small wrinkles in 4 to 5 weeks of soaking.
 
Most important that I forgot, thanks for posting as a big relief.
Barry
 
Barry said:
Thank you, not knowing was killing me.

I know what happened to you since it only reacted in one spot.
When I test, I spray two coats on a 4x11 panel laying flat on a 55-gallon drum.
When I dip the panel in dot3, it never attacks the epoxy but will creep under the epoxy where I did not have the edges covered.
Usually starts to show small wrinkles in 4 to 5 weeks of soaking.
Click to expand...

Yup, I had a leak on my front brake line and the same thing happened. I noticed a wrinkling of the paint where it got under the epoxy in a complex area that it was hard to get good coverage.
 
MikeS said:
Situations like this were one of the factors as to why I decided to use DOT5 fluid when I replaced entire brake lines and rebuilt the cylinders.
Click to expand...
Mike, DOT5 fluid solves one problem but creates another. It doesn't absorb water so condensation can settle in the bottom of the calipers and cause rust. Only way to get rid of the water is to dismantle the brakes. Bleeding or flushing doesn't get rid of the moisture because the bleeder screws are at the top of the caliper. This is one of the stainless sleeved calipers from my Corvette. The DOT5 fluid was in there for a long time.
DOT 5 Rust.jpg
 
While it it true that water will not mix with Dot5 and settle out in the low spots, the exact same thing will happen with Dot3 as well. Dot3 has a maximum moisture that it will hold before dropping out. This is not really a problem on most cars anyway. Any car that has a rubber bellows on the lid of the MC, most probably will never have a problem with moisture. This bellows isolates the fluid from the atmosphere and as the fluid goes down, the bellows follows it down. The old master cylinders, like in the 50's, had a cap with no bellows and the cap was vented to the atmosphere. The DOT3 fluid would slowly, over the years, absorb moisture from the air until it condenses out in the low spots in cold weather. Dot5 will not absorb moisture from the air as it is not hydroscopic like Dot3 is. Dry Dot5 will always stay dry as long as you do not add liquid water to the system. It is however the absolute WORST thing to have around paint work!



Regards, John McGraw
 
"...... It is however the absolute WORST thing to have around paint work!"
I agree, which is why I installed and bled the brakes last after I removed the temporary spray booth when the car was re-assembled. I put DOT5 fluid up there with other silicon based items like Armor All and tire sprays when it comes to not having certain items around paint work.

Mike
 
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