Has anyone got any experience in re-newing the underseal on their Mk2's? i'm wondering how much of a job it will be on my mk2 in my garage? I know there will be loads of scraping to be done, but is it a job that can be done on axle stands ? When replacing what would be the best procedure and products to use? i was talking to a fellow car friend and he took his back to bare metal with a wire wheel then etch primed and used Dinitrol stone chip, i was thinking of spraying on Raptor coating... but lack the knowledge and the internet is a minefield of misinformation...hopefully you guys will have a bit more knowledge to share? thanks in advance
id go for epoxy primer onto the bare steel ...great protection then depends on what you need on top of that , light summer use i would use a gloss /stain top coat , medium use maybe some overpaintable stonechip + paint , or raptor for heavy use ....bare in mind will it come off if repairs need touching in later on
well i was going to do any repairs / welding that i might find when i strip the underseal so hopefully it will not need doing for many many years after that. So thats why i was thinking Raptor/Dinitrol.. im not too worried about an OEM finish, i'd rather have something that was just great at protecting the car. theres then the question of seam sealing...looks liek its worth doing whil im under there. its probably one of those jobs that will be disghusting...time comsuming but worth it for the huge savings and peace of mind
Getting the old sealer off is a real ball-ache - hand scraping will take an age and if you can at all put the car on a rotisserie. Attempting to do this with stands will drive you nuts. A small electric grinder with the special wire discs will make pretty quick work of the old sealant but it goes everywhere and that will primarily be you if you're underneath the car with stands. When you do get it off, hand paint the base metal with zinc coating. This will protect against any further rust and then apply your sealant of choice - probably Raptor to get the best out of it.
It's possible to do this on stands but as above it does take an age. Having tried various techniques - scrapers/heatgun, pipe freeze etc, I found the best combo was a variety of twist knot wheels, some tunes and a surplus of colourful language. My repaint method was Bare metal > Electrox Zinc Primer > Epoxy Mastic > Seam Seal > Epoxy Mastic > Raptor tinted. The factory underseal is a love/hate relationship. It’s probably the reason so many MK2’s still exist but be prepared for what lurks beneath haha ... Good luck
The best thing I have used to get the rubberized underseal off is an electric scraper peels it straight off (also used a pneumatic one just as good) admittedly this was just for repair work rather than a whole car but saves all the spreading of bits of sealant just peels it off in long strips.
Just remember Raptor is 2k with some nasties in it - so ideally wear an air fed mask, which the typical diyer may not have. BH - epoxy mastic is 2k without nasties in it - hence the advantage. I'm not sure the benefit in layering both though?