• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

UNDER COATING REMOVAL

Share this page

B

BUCKEYE_BOB

Member
Offline
The undercoating on my MGB is all cracked up from age and heat, it was an Arizona car. I want to remove the undercoating to ensure there is no rust under it. What is the best way to remove it. The only way i can think of removing it is lay on my back and scrape it of. (All ready stripped the top side of the floor boards and only found surface rust and i will repair that). Once I remove the undercoating should new undercoating be applied? I will drive the car only in the warm weather.

Bob
 
I saw a website where a guy was using liquid nitrogen to freeze the undercoating and break it off. for normal people scraping is the best way. I'd reundercoat it, but I'm beginning to see people using Rhyno Liner instead
 
i'm currently stripping my undercoating - also off an ex-arizona car.

I have investigated a few fancy ways to get it off but really, only good old elbow grease and a twisted wire brush on an angle grinder works well. Its an awful job and takes forever but...

I plan to hippo coat the underside - I have heard it sticks better than the original style tar undercoating and is tintable.

tom c
 
I've also heard people using a Hot air gun or hair dryer to warm it up and make it a bit pliable as you pull it off.
 
And there are those who don't recoat, believing that the coating promotes pockets for rust to begin. After 30-40 years, it is hard to argue one way or another. Both ways have held up in som cases and gone away in others.
 
but I always figured the floors rust mostly from the top down due mostly to the undercoating
 
On my B Varsol was used to soften up the undercoating. The car was put on 4 realy big jack stands outside and the Varsol brushed on,a sguare foot at a time. When the undercoat softened it was craped off. A wire brush on the angle grinder was used to finish off. Real messy, goggles and protection needed. I have heard that a soda blaster will take it off. At any rate it is a uggggly task. After it was off I primed with 2 part primer and painted. The only areas now undercoated are the wheel wells.
 
On my MGA, I used heat to soften the undercoating, and a putty knife to scrape it off. I used a propane torch, and did a small area at a time. Just enough heat to soften, not burn it off! Then I used solvent to clean anything left over. I had all of the fenders off of the car at the time, and the floorboards were removed also. Not as much under the car work as a MGB. No matter which way you go, it's a slow, tedious job. Good Luck, and hang in there.
 
yeah Chris, I plan to undercoat the bejeezuz out of the red car after I get the floorboards done. If I planned to take ALL the old undercoating off I'd consider rhyno lining, but I ain't that ambitious
devilgrin.gif
and I figure they rust from the top down because of leaks and wet floor boards and carpets, the undercoating protects the bottom

[ 02-08-2004: Message edited by: Chuck Cougill ]</p>
 
that's my plan - seal the inside footwells right up using white tinted Rhino truckbed liner. Trunk as well. Don't think I'll do the engine bay - leave that smooth. So the overall plan

strip of undercoat with grinder/wire brush - done
clean/wash
2 part primer everywhere
rhino on underside, trunk, floorboards, wheelwheels.
prime/paint everything else.

tom c
 
i did my floorboards with Dynamat extreme. its waterproof and once its on, its not coming off. makes the car quiter too and its easy to put on.

Dr.
 
I did my 'C' last summer and it turned out great.
I jacked one side of the car so the bottom of the tires were at least a foot off the ground. I then used liberal amounts, eight 19.2oz cans of Gunk Heavy Duty Engine Degreaser. Let that sit for 30-40 minutes and then followed that with high pressure washer(1500psi)using the fan tip. Some stubborn areas required a couple treatments, then what little under coat didn't come off after that, I scrapped off and then re-HP washed. After letting it all dry overnight, I then came back with 3M Underseal Rubberized Undercoating, Part# 08883. I used 7 or 8 19.7oz cans. I was very happy with the results.
 
Back
Top