Remove old underseal first?

[24OZ]

My car has been pretty well undersealed... but i would like to do it again as some areas are begining to flake..

I dont think its a good idea just to paint over old underseal so i need to remove the old stuff. (anyone disagree??)

Any ideas how to remove underseal which is extremely sticky (tar like)? I tried to scrape it but it just spreads it around and makes a mess...

By the way, I plan on using POR 15 to underseal the car, after reading some good recommendations... (that should do the trick shouldnt it?)

Thanks all.

[JEFF]

I would remove an area large enough to expose the flaked area plus a little. undercoat what is needed that way. If you are willing to do a Full strip then do so. That project is very messy and lengthy. Prepare to spend some time under there. ( wear safety glasses nomatter how sweaty your face gets ). POR15 is an exelent product - be sure to use it as manufacture recomends.

2 cents worth.

- Jeff

[2ManyZs]

Definately strip off any cracked or chipped areas as you might have moisture in behind it doing you know what....

Eastwoods has a pretty good undercoating remover, don't know if you can get a like product over there, but it does help to soften the undercoating and makes it so much easier to remove, and they have another product that gets rid of the leftover undercoating residue....

You can heat it with a fairly decent work lamp, such as a 350 or 500 watt halogen type worklamp or you could use the dry ice/chipping method. I'd go with the heat from the halogen worklamp as it is a bit safer on the fingers...

If you do part of it, I'd go ahead and do it all, and coat it with POR-15... that way, if anything is hidden under it, you can find it and repair it if needed....:disappoin

[Bambikiller240]

George:

I have a method for your consideration to remove the undercoat. I've done it this way and it works well for me. I use an hand-held hiar dryer gun to warm an area so that the material is softened, in the other hand I have a 2 inch wide paint scraper, and I scrape it off as it softens. There will still be tiny bits of it left, but they wipe off with a rag soaked in Acetine, or other solvent.

If you are considering the POR15 treatment, remove ALL of the undercoat, follow the POR15 instructions TO THE LETTER, and you will be amazed at how well it works. After the POR treatment, you could re-apply undecoat as a sound deadener & additional protention of the metal if you wanted.

[24OZ]

Jeff, Keith, Carl,

Your experience in these matters are so very much appreciated, especially to someone who has had very little, if any, experience in restoration/preservation.

I think I will go for the Heat method, now I dont have one of those fancy work lamps but I know a sister of mine with a fancy hairdrier.. :classic:

(I give her 5 minutes before she notices it's missing...)

Thanks guys

[26ounce]

Removing this stuff is slow and tedius work! I spent a couple of hours under the car yesterday and have only removed a very small section, and even that area still has a lot of residual undercoat left behind.

I was using a hair dryer and while it worked alright you don't exactly zip through this stuff. Guess I'll try and find some of this underseal remover stuff.

[Ed]

On some of the factory sound deadaning(sp) material on the inside I've noticed that after I tap it with a hammer a few times it detaches from the body, thus making it come off in large pieces.

I actually found this out when I was banging away at the floor boards in an effort to try and straighten them.

[Murph]

I'm currently doing mine using a knotted wire wheel on an angle grinder. My tar is a little harder (quite new though) so it works quite well and takes off the old undercoat.

Still takes a fair bit of time to do.

Just make sure you wear excelent eye protection, and dust mask isn't a bad idea and I found out the hard way, wear a shower cap! I now have a scalp covered in bloody tar!

[24OZ]

Good idea on eye and hair protection:).. Shower cap must look real funny though.. I prefer a baseball hat

It really does get messy when using a drill with a wire wheel, especially if the underseal is brittle and old. Bits go everywhere..

[Murph]

If the digicam wasn't in getting fixed I'd take a pic of myself in all the gear for everyones amusement.

[26ounce]

Hey 240Z, if the underseal is brittle and old just get after it with a paint scraper. Using a scraper I zoomed throught the brittle sections on mine in no time, and had the added bonus of not having to wear shower-cap.

It is the thicker gooey parts that are giving me the most problems, if the wire wheel works for you here then go for it.

Carb cleaner is my solvent of choice for getting rid of any residue, more expensive but does a great job.

[24OZ]

Totally agree with you 26ounce, scraper can be very handy when doing the brittle stuff, as I had too on the 280zx. The 240Z is all thickly coated and goooey.... thats where it gets harder.

Dattoo, when do you get the digi cam back? I wanna see this pic .. It will not only be amusing but also educational... ie.. what you should wear when working underneath your Z ..