Bloody Underseal!

[Jan]

Some blind idiot has 'repaired' the inner sills of my motor home with random squares of plate (some on top of each other and only fit 'where they touch') and then blasted the whole area with underseal. As I need to shape several plates - to actually fit the odd shapes involved - and then weld them in place correctly to pass the MOT I'm up against a lot of underseal in all too many corners where a wire brush just won't go. Short of blasting the area with sand/grit/glass beads, on the road, what are my other options to achieve a decent cleanliness to accept a weld? I'd prefer to use MIG, but am willing to fall back on stick if necessary.

 

[richie00boy]

Go to Toolstation or local motor factors and get a Silverline decarb wire brush set. If access is difficult get a flexible drill extension.

 

[pedrobedro]

Hot air gun and scraper works for black gunge underseal.

 

[Wendelspanswick]

For tight corners and gaps a needle scaler attachment on a cheap air chisel works well.

 

[711jrp]

Check to see if thinners attacks it, some old hiderseals can be scrubbed off with a stiff brush.

 

[ibrooks]

White spirit tends to be good at removing underseal - obviously it depends on just what type of seal it is.....

 

[rich r]

As above - if it's paraffin based (eg Waxoyl), then it'll dissolve in solvents such as thinners, white spirit, petrol etc. Obviously it's a messy job, but you should be able to clear enough of it with soaked cloths to get the job done.

 

[razordog]

Best thing I,ve found for removing anything that aint metal is the wire brush attachment that goes on 115mm grinder, make sure you are well protected, ie gloves overalls safety glasses. The problem with trying to dissolve it for me was it smears and what is left behind sets alight.

 

[Wallace]

It's a messy laborious job, I had to do a floorpan earlier this year. Depending on the type of underseal, a 1" paint scraper regularly sharpened can work wonders at removing the bulk and cellulose thinners or white spirit if it's sticky bitumen based.

 

[God mode restorations]

I used hot air gun and a good scraper..works well.then wipe down with panel cleaner..get even the real tuff stuff off.

 

[mike 109444]

A fire watcher might be a good ideal if any one is available. A bucket of water and or sand. If away from house ("on the road") That's not the time to find your hose pipe does not go that far! Small spray bottle with water to catch any small flames. Stop regularly and lift helmet to check for flames including top side. If all else fails then it's 99 and another 9

 

[octo0072000]

Remember all that flammable insulation that's stuffed into the panels as well

 

[Jan]

I think I'll have a go with my pressure washer. Added to my already excellent rising mains pressure and using the finest water jet it can shift almost anything.