Rust penetrant safe for fiberglass

[Joseph R.]

Hello, new forum member here. What is a penetrating catalyst for rusty threads (like PB Blaster, WD-40, etc.) that is effective but safe for use around fiberglass and won't cause future bonding or paint problems? PB Blaster dissolves some plastics and the manufacturer's website states it is not safe for fiberglass. Are there better alternatives for Corvettes?

I am a new owner of a 1964 convertible that has been sitting since about 1972, so I'm looking at complete disassembly of the drivetrain and probably body off process. I will be spraying a lot of thread release rust penetrant and don't want to damage the fiberglass with the inevitable overspray and drips. Thanks.

[Russ T.]

Re: Rust penetrant safe for fiberglass

Joseph,

You could be in a "world of hurt" by doing this. I had the problem with penetrant
soaking into fiberglass on 2 doors and could not repaint doors properly and had to
replace them.

Apparently a previous owner sprayed penetrant inside the door and it got sucked into
the fiberglass. I stripped the paint off the exterior of the door and left it
in the summer sun every day, wiping it down regularly with lacquer thinner.
I never did get it all out. It stayed "blotchy" where the penetrant was
coming out the exterior of the door, and I didn't attempt to
paint it again, just replaced the door.

Others may have had different experiences, but I would avoid doing this
based on my experience. If you must use spray penetrants, I would definitely
advise carefully masking off the fiberglass to prevent contamination. Perhaps use
a medicine dropper to apply a liquid instead of spraying, but avoid any contact with fiberglass
at all cost if for nothing but peace-of-mind.

Russ Trotter
NCRS #15044

[Edward J.]

Re: Rust penetrant safe for fiberglass

Joe, my advice is remove the body first, If you need to spray anything to remove the body mounting bolts, bumpers bolts use a rag and wrap to catch the over spray. fiberglass that is raw/bare will absorb like a sponge.and crate problems down the road with paint.

[Paul J.]

Re: Rust penetrant safe for fiberglass

Hello, new forum member here. What is a penetrating catalyst for rusty threads (like PB Blaster, WD-40, etc.) that is effective but safe for use around fiberglass and won't cause future bonding or paint problems? PB Blaster dissolves some plastics and the manufacturer's website states it is not safe for fiberglass. Are there better alternatives for Corvettes?

I am a new owner of a 1964 convertible that has been sitting since about 1972, so I'm looking at complete disassembly of the drivetrain and probably body off process. I will be spraying a lot of thread release rust penetrant and don't want to damage the fiberglass with the inevitable overspray and drips. Thanks.

Welcome to the forum. The preferred penetrant is Kroil or Aerokroil. It performs better than PB Blaster. WD-40 is not a penetrating oil.

As the others have said, you may have to do some wiping (or soaking) with lacquer thinner if you get too much of this on bare fiberglass. However, there are only a few painted fiberglass surfaces that you might want to watch out for, otherwise, I wouldn't worry too much about it.

Paul

[Joe R.]

Re: Rust penetrant safe for fiberglass

Hello, new forum member here. What is a penetrating catalyst for rusty threads (like PB Blaster, WD-40, etc.) that is effective but safe for use around fiberglass and won't cause future bonding or paint problems? PB Blaster dissolves some plastics and the manufacturer's website states it is not safe for fiberglass. Are there better alternatives for Corvettes?

I am a new owner of a 1964 convertible that has been sitting since about 1972, so I'm looking at complete disassembly of the drivetrain and probably body off process. I will be spraying a lot of thread release rust penetrant and don't want to damage the fiberglass with the inevitable overspray and drips. Thanks.

Joseph,

I would recommend contacting Gene Manno through this board. He wrote an article for the Western New York chapter newsletter that showed the results of a test of various penetrants. I believe a home brew mix of 50 / 50 acetone and ATF (automatic transmission fluid) was the winner.

Joe

[Paul J.]

Re: Rust penetrant safe for fiberglass

Joseph,

I would recommend contacting Gene Manno through this board. He wrote an article for the Western New York chapter newsletter that showed the results of a test of various penetrants. I believe a home brew mix of 50 / 50 acetone and ATF (automatic transmission fluid) was the winner.

Joe

This is correct, but for some reason people don't like to mention the home brew. As I recall the acetone/ATF mix worked far better. The test results and other related discussions are in the archives.

[Joseph R.]

Re: Rust penetrant safe for fiberglass

Joe Raine, based on your tip, I found the following about penetrant's effectiveness in the March 2013 Western New York Chapter newsletter - there is more info there about the test conditions in the original Machinist Workshop Magazine report. I couldn't find anything about Kroil's safety for use around fiberglass at the kanolabs website. Eye dropper application for all these seems like a good approach around fiberglass. The cautions are well taken, unless someone knows of a product that will definitely not harm or penetrate fiberglass, yet still free up rusty nut and bolt threads.

This is what they came up with:Nothing: 516 lbs.WD-40: 238 lbs.PB Blaster: 214 lbs.Liquid Wrench: 127 lbs.Kano Kroil: 106 lbs.(ATF)/Acetone mix (50/50): 50 lbs.This last

"shop brew" of 50% automatic transmission fluid and 50% acetone appears

to beat out the commercially prepared products costing far more.

[Ara G.]

Re: Rust penetrant safe for fiberglass

Joe, I am not hijacking your thread, but I noticed your member number....NCRS is so close to 60,000 members...that's AWESOME.....Welcome aboard...ARA

[Jim D.]

Re: Rust penetrant safe for fiberglass

Joe, I am not hijacking your thread, but I noticed your member number....NCRS is so close to 60,000 members...that's AWESOME.....Welcome aboard...ARA

Member numbers are not recycled so the actual number of members is only a fraction of 60,000.

[Ara G.]

Re: Rust penetrant safe for fiberglass

Member numbers are not recycled so the actual number of members is only a fraction of 60,000.

I know Jim, but it's still cool to see "total" membership nearing 60K.....

[Bob S.]

Re: Rust penetrant safe for fiberglass

Joe,
Loctite has a new product called Freeze and Release. I have not used it yet personally but have heard it works well. Same priciple as heat but without the chance of burning your car up. Not sure if it has any properties that would soak into the fiberglass.

[Bill W.]

Re: Rust penetrant safe for fiberglass

Joseph If you do get oil or brake fluid of any kind on raw fiberglass dont use lacquer thinner use enamel reducer , I like Dupont #3812 .