[DeTomaso] Undercoating removal?

[Garth Rodericks]

Cullen,

To echo what others have already said, removing the undercoating is a dirty, messy, difficult, miserable job! That said, let me share what I've learned in the process of removing it from my engine compartment...

The methods I've used/tried so far, and I still have more to strip after 6-9 months:

1. Heat Gun - Purchased on sale at Harbor Freight for $9. Heated the undercoating then scraped with a plastic paint scraper. Worked fairly well on the large mostly flat surfaces. Although, I was suprised how much weld splatter (tiny drops of weld) was all over which prevented the scraper from sliding smoothly across the panel. This actually made it a pain in the derriere. Heat gun and scraper were totally ineffective in all the tight corners and joints in the lower engine compartment. Lots of burns and burnt hair too - be careful where you point that thing while you're trying to shake off all the gobs of undercoating sticking to your putty knife/scraper. And don't let the tip of the heat gun accidentally touch or brush against your arms. This is the voice of experience.

2. Wire wheel on a die grinder air tool - removed the undercoating quite well from the larger fields, but unable to get into all the small spaces in the lower engine compartment. This area is really challenging. It also "rained" tiny bits of undercoating ALL OVER the garage. Did I say it threw the stuff ALL OVER the place, at 20,000 rpm. I had this stuff falling out of my hair and ears for 3 days despite all the showers I took - ok, maybe not 3 days, but you get the point. Cover up well if you go this route, and wear safety goggles!

3. Lacquer thinner, paint thinner, mineral spirits, and gasoline - Yup! I tried them all. Basically worthless to remove the bulk of the thinner. Others told me how the laid rags soaked in the chemicals on their inner fender wells, and everything just scraped right off - didn't work for me. And try doing this on the underside of the car, near impossible. The only thing these chemicals were good for was wiping down panel to remove all the excess undercoating residue left by the scraper. Note that I found the lacquer thinner to be the most effective. The other required more work for the same result. And the gasoline caused too much fear that I'd bump something or drop a screwdriver causing a spark and sending me to meet my maker - not good!

4. Torch - Yes, tried that too!  Quite effective to clean out all those spot weld dimples still filled with undercoating. Apply the torch for a moment then wipe with an old rag. Quick and clean. Tried it to remove the undercoating from all the messy weld joints and slag around the camber bar brace pockets and other welds; not effective. The weld joints are a sloppy buggered up mess with lots of holes and crevices. You can't scrape the undercoating out. You also can't cook it out with the torch; it just boils. I was hoping I could cook it to a crisp then just brush it out with a small wire brush - no such luck.


If I were to start this project again, I'd use AIRCRAFT STRIPPER. A fellow club member stripped all the undercoating from his engine bay in one evening with some industrial aircraft stripper. 5 hours start to finish! It's a messy job, but effective.

And another club member stripped the undercoating from the underside of his car in 2-3 hours with an auto-body air tool with were heavy stout wires instead of fine bristles. See the DF-701 Right Angle Undercoat Remover on page 12 of this catalog: http://www.dentfix.com/catalog/df-catalog.pdf

Cheers!
Garth