16 replies to this topic

[Laurie]

The bottom of my 'new' project (1971 mini) is smothered in underseal, I'm of a dilemma to keep or remove to be honest
Both options have their pros and cons, on the plus side it helps protect the bottom of the car from certain damage. On the minus side it hides a few sins as well- rust/ appalling welding and so on.

So...what do you think of it?

[Matt.L]

Personally I'd get rid of it and stone chip the underneath then top with the paint colour of the car. Leaves a much cleaner finish:)

[THE ANORAK]

my current mini was and is plastered with under seal and im in the process of cleaning it off.

 

all i can say is, where it has stayed undamaged it has protected the car very well, but where it has let the water through ( rear valence closing panels) its a bloody mess !!!

[MatthewsDad]

As above, highly unlikely it's all intact. Any small areas that have detached from the underside will be concealing corrosion. If you have the time and patience, strip it off. If not, keep an eye on it, scrape off loose stuff as it appears, use a rust killer on the exposed metal, and then a decent underseal like Bilt Hamber UB.

[AVV IT]

I say get rid! What appears to be a perfectly in tact layer of underseal can conceal a whole load of horrors that are silently rotting away underneath.

[Neville1971]

What is the best method of removing old underseal?

Wire brush, scraper, sanding?

Using a drill, grinder, by hand, compressed air tools?

 

It's the next job unfortunately

[dyshipfakta]

Heat gun and scraper works well

[tiger99]

Sometimes it can be softened by White Spirit but I don't know how you would keep the underside wet for long enough unless the shell is on a spit. It may be useful locally if you work it in with a stiff brush.

Sad to say, underseal was a short term bodger's remedy, like oversills, but it is still sold and most people including many garage mechanics have no appreciation of the long term harm it always causes.

It is best to rely on a full paint process, starting ideally with zinc, or more likely an etch primer, followed by an epoxy primer, before applying stonechip. I fear that stonechip on its own may turn out to be as bad as underseal, as is powder coat once it is damaged. But you don't need a high build primer and lots of flatting under stone chip. Doubtless some real fanatic somewhere would....

Please wear a disposable hat and face protection as you are going to get very mucky. Sadly there is no fun to be had in removing underseal.

[sonikk4]

If the car was Ziebarted from new like mine was then there is every chance rust will have worked its way in (its never guaranteed for life.) Mine scraped off as it was hard then washed over with celly thinners.

 

My clubby once cleaned off and repairs done, everything was sprayed in Epoxy primer, then followed by 3 coats of stone chip. Not heavy coats though. Then it will be topcoated.

[MatthewsDad]

Hot air gun, but instead of scraping off while hot and gooey, try allowing it to cool and repeat a few times over a few days. Whatever makes it sticky is driven out by the heat and the sealant becomes more brittle and easier to chip off. Do a small area at a time. Slow dull job.

[Neville1971]

Thanks for the replies.

 

No one is selling this job to me but it has to be done  .

I'm just waiting for my father-in-law to empty his garage so I can get her over the pit (Which hasn't been used for countless yeas apparently so that will be fun in itself)

[Laurie]

Thanks for the replies.
 
No one is selling this job to me but it has to be done  .
I'm just waiting for my father-in-law to empty his garage so I can get her over the pit (Which hasn't been used for countless yeas apparently so that will be fun in itself)

Just watch out for the massive hairy spiders that will grab you by the throat and try and suck the life out of you lol!

[danie garry]

 

Thanks for the replies.
 
No one is selling this job to me but it has to be done  .
I'm just waiting for my father-in-law to empty his garage so I can get her over the pit (Which hasn't been used for countless yeas apparently so that will be fun in itself)

Just watch out for the massive hairy spiders that will grab you by the throat and try and suck the life out of you lol!

 

 

awful thing to call a mother in law!

[Laurie]

 

Thanks for the replies.
 
No one is selling this job to me but it has to be done  .
I'm just waiting for my father-in-law to empty his garage so I can get her over the pit (Which hasn't been used for countless yeas apparently so that will be fun in itself)

Just watch out for the massive hairy spiders that will grab you by the throat and try and suck the life out of you lol!
 

 
awful thing to call a mother in law!

Hahahaha! That really made me laugh out loud lol 😂

[Stu.]

Underseal products are not the problem. The problem is that most folks think one application will last 5 years. 

 

It needs to be cleaned off and re-applied very regularly, most likely twice to three times a year.

 

Even when driving only in the dry, underseal will be eroded from the base of the inner wings and sill fronts due to dry road dirt from the roadwheels.

 

Regular inspection and re-application is the key.