What is the most effective abrassive disc to remove undercoating?

I am struggling with undercoating under my floorboards and i need to remove this before i weld up new sections. I have been using 36 grit 3 inch 3M roloc disc but they get gummed up very quickly and are not very efficient. I used a Propane torch and a scraper to get the thickest stuff off, its a freaking mess and a PITA job.

I plan to hit the tool store to see if i can pick up a better disc or even a wire brush but i wanted to recommendations on what works best before i piss money away on stuff that wont work.

 

let the car metal get cold, and it chips off.


any abrasive disc will just heat it and smear it.


try the cold deal; if you get a good quick push, it keeps going. Not just a tiny flake at a time.

 

how can i possibly get it cold? this material on here is like the nastiest i ever come across on any of my cars. it isnt thick enough to chip off its a very strong uniform coating almost like a bedliner in sections but its bonded to well.

 

Torch and a puddy knife is what I use, comes right off

 

Eastwood sells a product in a spray can that removes under coating.

 

oh, you must live in "southern" nyc, where it stays warm?

Open the shop on a brutal cold day, or push it outside.

I use various widths of plastic handle wood chisels. Find the right width that peels it good. Some thicker undercoats need a narrower one to get started.

I have a 37 ply in the shop with nasty thick soundproofing tar crap, and if you set the blade tip right, and give it a good shove, it breaks off like glass.

 

I’ve used the surface conditioning or paint and rust removal disc with some success. They do wear rather quickly though. Maybe after you get the heavy stuff off you could go over it with those discs.

 

Now can i use lacquer thinner to remove the residue after scrapping it off? whats the deal with the Eastwood product has anyone used it to comment? does paint stripper offer any help?

it would be awesome to find a chemical that will just eat this cap up and i can just clean it off

my garage is like an ice box and trust me it isnt helping once bit.

 

yeah they work well but they wear quickly and are so expensive to buy. i went through a box of 25 already and really didnt get much accomplished considering how last of the area i need to clear.

 

x2 on the torch and putty knife. Keep it moving and get it warm, scraps right off with most of the time only a little clean up needed after. We blast cars at our shop and this is by far the fastest most economical means.

 

Air hammer with a wide flat chisel works great on the flatter areas. Any solvent will soften up the thin stuff.....still messy though

 

Squirt it with liquid nitrogen.

 

I have removed it from sheet metal/body parts when it's cold by using a rubber mallet. If you hit it with the mallet it makes a momentary arc in the metal and a shock wave. It will come off or atleast break the bond so it can be chipped off easier. For thicker steel and hard to reach areas, chisels or scrapers of different widths, make sure they have rounded corners so they dont leave gouge marks.

I wonder if the nitrogen idea would work?

 

Dry Ice Pellets works a treat. Leave it on for a few minutes and give it a sharp crack with a rubber mallet [ it scrapes off real easy ]

Here's a Ewetube link I found .but with my experience with it ,I prefer to wait a little bit longer and go easier with the "hitting stick"
http://www.youtube.com/watch?v=onR0VrOg-Ks



After that drop a 6-pack in the dry ice [ no longer than 30 secs or it freezes ] and treat yourself to a cold one.

Or have a cold one while waiting for the sound deadener to freeze

 

I use one of these multi tools.
Works a treat and real easy too.

 

Get yourself one of these and zip that crap off in no time...........

 

Flame is too dangerous, a friends car had that stuff under it and had to have a muffler clamp welded. The guy didn't scrape the goo away and it caught fire. Try a heat gun and putty knife.

 

bet your shop teacher likes this idea



I use various widths of plastic handle wood chisels.

 

I'd avoid anything to do with heat.
WAY too messy.

 

I have used a heat gun & putty knife, time consuming and not fun but it works, then use lacquer thinner to get the remainder.

 

my heat gun has an attachment for just that purpose ---do some on line shopping

 

I heard stories about packing the areas with dry ice and it would come off.Drag racers used to do it to lighten cars tears ago

 

If you are welding in new sections, exactly how much do you need to remove?
I'd take just enough around the perimeter of the patch.

 

This has been the best method I've found too.

 

The easiest way to remove under coat is to cut the old floor pan out and weld new in....( LIFESTYLZ idea is a good one, So is Waddayacare's idea. This is one of those no easy solutions!

 

There is a vid of the tool waddayacare posted in action. It looks pretty good. There are several different systems shown. The dri ice is a good one also.

 

OOPs! I forgot to tell you where to look. youtube has quite a few vids.

 

A) Jackhammer

B) Plastic explosives

Seriously, there's no easy way to remove the stuff. It's just no good dirty, shitty work that you have to get through. Might be quicker and easier to sell the car and buy a duplicate that was never undercoated or already has good floors.

 

A torch and a putty knife work best. Be careful that you don’t get it hot enough to catch fire and drip off. It has an uncanny knack to land on your left arm.

<OOf course, the first reaction is to wipe it off with your right hand.

<OThe second reaction then is to wipe your right hand off with your left hand.

<OBy that time, you realize that the trick with your right hand was not the most intelligent thing that you have ever done.

 

Dry ice works like magic. Break up chunks with a hammer and spread the powder around. In a minute or two you'll hear cracking, big chunks of that rubber shit will just lift off the floor.