Thinking of getting the car treated underneath, sills, arches boot floor etc but wanted to ask what product is best to use as waxoil and underbody seal seem to do the same thing and wanted to ask if anyone here knew what the difference was.

The corolla is going to be 12 years old this year and so far the underneath is looking solid just wanted to get it treated ready for the winters ahead.

Thanks everyone.

Waxoyl is wax and white spirit based so can be thinned with white spirit and penetrate small gaps and crevices, you can buy a cavity wax gun and spray it yourself, compressor needed though. Normal underseal can't be thinned as easily and needs to be applied the same way to get into the crevices but not as affective. You can brush either but its a messy job. Both are best applied in warm weather so the fluid runs better. I've done a few classic cars years ago and it takes a good 2 days to do it properly. If you are paying someone it could work out expensive as it does take time to protect the car proper like.

Edited 25 January, 201115 yr by Soot1e

Also Waxoyl, to a degree is self healing, so if it does get a knock it respreads itself, whereas underseal gradually goes hard, and if knocked can start to peel and let water under.

Forgot to say, using waxoyl, you only need to mask up the exhaust, spraying liberally under the car doesn't harm rubber pipes, bushes, electrical wiring etc. and is easy to wipe of bolts with white spirit when disassembling parts that need changing.

Cheers - Looks like waxoyl it is then, will look at this when the weather gets a bit warmer, thanks.

Hardened underseal can crack and let moisture in which can accelerate corrosion, you're better off with wax.

Hardened underseal can crack and let moisture in which can accelerate corrosion, you're better off with wax.

+1

Also, in a couple of years you can re-apply Waxoyl to the arches and floor, and get a thicker but still flexible coating. With underseal you'd have to strip the hardened stuff off first.

I'm a member of the Citroen AX forum....mainly full of young lads and chavs sadly, but one of them has just posted some pictures of the underside of his fine looking mk1 GT that he's just treated with Scultz, which is apparently very similar to Waxoyl.

Looks awesome, but was apparently hard and messy work.

Need to do mine now I think, so if any one knows where I can hire one of those 'tilting' contraptions, I'd be much obliged!

Yep, Shultz is half way between Waxoyl and normal underseal, still a messy job though.

Mr Ree Look for those "Contraptions" on Classic car Forums 2nd. hand, they tend to get used once and sold on, never seen them for hire.

You don't need a car spit for Waxoyl; just a pair of axle stands and the preparedness to spend an afternoon lying on your back with your head and chest under the car.

it depends which undersealer you use, the cheap halfords tetroseal stuff is crap, if you use decent stuff it doesn't crack, also you can get spray on sealers which are polyurthane based which are 100% waterproof forever!