Undercoating Removal Ideas

[Troy]

Ok, I thought I'd help out a fellow member by doing some research on the internet this morning. I never did find what he was looking for but I found a bunch of other cool stuff that deserves its own thread. Undercoating removal (or "how do I get this stuff off?") is a topic that comes up relatively often. We've discussed various ways to accomplish this task and most are messy, smelly, time consuming, lots of work, and somewhat dangerous. I have removed undercoating in the past with a screwdriver (chipping at it) and with heat and a scraper. Neither is fun or fast. Stripping wheels, sandpaper, and sandblasting all tend to give undercoating the consistency of chewing gum and it still doesn't come off. Pressure washers seldom work. Gasoline seems to work but I'd question the mental capacity of anyone soaking the underside of their car  in it. Well, apparently we aren't the only ones who've ever tackled this kind of project so here are some links to other ideas (click on the underlined words):
Testing a variety of methods including chemicals and all sorts of stripping/sanding devices.
(Not to spoil it but they found that a braided wire wheel on a grinder doesn't get gummed up and that some chemicals work much better than others.)
AWESOME! The Dry Ice Method - and when you're finished you can make fog for the kids!
Another gearhead discussion - what works and what doesn't.
The Oven Cleaner Method - choose wisely.
Simple Green Method - biodegradable mess?

I'll be trying out some of these methods in the future so I'll try to keep this thread updated.

Troy

[BigBlockSam]

i've tried all kinds of stuff. the only way i've found is a scrapper and a hammer. some come off when i sand blasted it but alot did not. Rene

[694spdRT]

Thanks for the info Troy.

The previous owner of my '69 was kind enough to cover the entire underside with roofing tar. I took off the intial layer with a heat gun and scraper, then a braided wire wheel on a grinder to get off what was left, and finished with sandblasting the entire underside.

I should mention having it on the rotisserie helped tremendously with this job.

[hemihead]

I think i will try that Dry Ice method, unless i can get my hands on some liquid nitrogen lol 

[ck1]

Ok, I thought I'd help out a fellow member by doing some research on the internet this morning. I never did find what he was looking for but I found a bunch of other cool stuff that deserves its own thread. Undercoating removal (or "how do I get this stuff off?") is a topic that comes up relatively often. We've discussed various ways to accomplish this task and most are messy, smelly, time consuming, lots of work, and somewhat dangerous. I have removed undercoating in the past with a screwdriver (chipping at it) and with heat and a scraper. Neither is fun or fast. Stripping wheels, sandpaper, and sandblasting all tend to give undercoating the consistency of chewing gum and it still doesn't come off. Pressure washers seldom work. Gasoline seems to work but I'd question the mental capacity of anyone soaking the underside of their car   in it. Well, apparently we aren't the only ones who've ever tackled this kind of project so here are some links to other ideas (click on the underlined words):
Testing a variety of methods including chemicals and all sorts of stripping/sanding devices.
(Not to spoil it but they found that a braided wire wheel on a grinder doesn't get gummed up and that some chemicals work much better than others.)
AWESOME! The Dry Ice Method - and when you're finished you can make fog for the kids!
Another gearhead discussion - what works and what doesn't.
The Oven Cleaner Method - choose wisely.
Simple Green Method - biodegradable mess?

I'll be trying out some of these methods in the future so I'll try to keep this thread updated.

Troy

Simple Green is biodegradable Troy, I don't know how it works on undercoating but I know for a fact it removes X-mas tree pitch or fir tree pitch off hands and pruning tools for I co own a tree farm wait a minute i gonna have to check the biodegradable factor? never thought of that, just took my Moms word for it it was safe on the hands, skin so soft from Avon works good on pitch too I wonder if it will remove undercoating LOL

p.s. the web site says it biodegradable

[Troy]

Hmmm, I think I said it was biodegradable didn't I? The "mess" part of what I wrote is because you'll be left with a big pile of goop on the ground if it works. I added the question mark because I'm not so sure that the undercoating and the rest of the crud that comes off with it will be as biodegradable as the Simple Green.

Troy

[Charger_Fan]

skin so soft from Avon works good on pitch too I wonder if it will remove undercoating LOL

If it does, write Avon a letter & tell 'em what you used it on...I bet someone faints.


Thanks for the links, Troy!

[694spdRT]

skin so soft from Avon works good on pitch too I wonder if it will remove undercoating LOL

If it does, write Avon a letter & tell 'em what you used it on...I bet someone faints.


Thanks for the links, Troy!

It definately works good on the Knats that bite you while you are scraping off the undercoating. 

[JimShine]

Aircraft stripper softens it right up and it will scrape right off.

[rare69]

just did the intire underside of my 69 charger. my cousin owns a custom rod and restoration shop and lent me one of his rotisseries and the way he does it and told me to do it is with a small handheld propane torch and a putty knife it worked great. just heat the undercoating up with the torch and scrape the stuff off. didn't take as long as i thought.

[chargermick]

I removed my seats and carpets, put two 500 watt halogen lights right on the sheetmetal. Waited 5 minutes, went under the car and scraped it off with a scraper. Cleaned up the residue with mineral spirits. This worked well for me.

[Drop Top]

I do it the way rare69 did his all the time. I can't tell you how manny cars I have done this way. I have tried some of the ways that were mentioned. Including dry ice. The dry ice method is a bit expensive by the time you get it all done, and hard to work the ice with your hands. It freezes to everything it touches. Including your gloves. It just a big pain in the rear. When using a small propane torch. A small wire brush will help get in those tight areas. Its reatively cheap to do it this way. One bottle of propane will usually do the job and have some left over. If your doing it on your back becareful that you dont let it drop on you. It will burn you if your not careful. Its much easier if the car is on a rotissery. If you really want it clean wipe it down with laquer thinner afterwords. Just remember its flamable. A propane torch also works on geting large amounts of bondo off the car. Just becareful with it. The bondo will catch fire. You don't want to over heat the metal eather. You will distort the metal if you do. Just keep it on the bondo and when it starts to bubble. Take your putty knife and scrap it off.

[Charger_Fan]

A propane torch also works on geting large amounts of bondo off the car. Just becareful with it. The bondo will catch fire. You don't want to over heat the metal eather. You will distort the metal if you do. Just keep it on the bondo and when it starts to bubble. Take your putty knife and scrap it off.

That's good to know. That would be much easier than trying to sand all the way through a big gob-o-bondo.

[mopar_madman]

I've tried the eastwood brand undercoating remover, barely worked on the factory stuff still needed lots of muscle with the scraper but helped when I got the real heavy stuff off. But I used it on some 3m undercoating that was put on my car about 15 years ago and worked great on that.

[bull]

The dry ice method sounds like it would work pretty slick but only if the car was upside-down.

[The Ghoul]

I had luck with the paint removing heat gun and scraper being very careful not to work directly above you. Then finishing with the wire wheel in the grinder.
Just remember the wires come flying off and are hard enough to pull out of cloth and skin much less an eyeball!!!
so safety gear is a must!
respirator better than just a dust mask
full face shield
and ear plugs, other than the noise created by the empty shell reverberating but this crap is hard enough to get off the car or the skin but much less from in your ear!

[bull]

Wolfman Jack rides again.

[rare69]

must have been a full moon that night!

[4402tuff4u]

I looked exactly like Cudaeh did when I did my Charger. I found the best results with a 4.5" grinder fitted with a straight heavy rigid welders wire wheel. Make sure you hold on to the grinder like you mean it! It took me 2.5 days of work to complete it. It sure is a messy job! The dry ice method sure does sound interesting.

[Mfr426]

Great shot! I thought I was the only nut? My neighbor calls me "Mr. Safety". Guess where he comes to get things fixed though?

[The Ghoul]

as goofie as I looked after I was very impressed with the results

[Doc74]

cudaeh you should get those pics on a poster ad and have one put up in every body shop ! You can almost make out which brand respirator you were using  imagine not using one and your lungs would look like your ears !
You mind if i print these off, I got some idiots in the shop who still think they can beat the dust      

I'm glad some people actually think before they act and btw excellent work,that front looks great, what stage is it in now ?

[The Ghoul]

cudaeh you should get those pics on a poster ad and have one put up in every body shop ! You can almost make out which brand respirator you were using  imagine not using one and your lungs would look like your ears !
You mind if i print these off, I got some idiots in the shop who still think they can beat the dust      

I'm glad some people actually think before they act and btw excellent work,that front looks great, what stage is it in now ?

Feel free man, but Ill warn you if I end up on a porn sight... I'm gonna kiss you!!
The car is in a holding pattern. I stripped down the underbody, roof where the 3/4 top goes, engine compartment and wheel wells. I painted all the bare with por-15, mist coated the engine compartment with primer. I am ready to start tacking in new metal, filling pitted metal, and stiffing it as much as possible. I decided to stray away from the por-15 and after the new metal is I'm going to have the shell and doors media blasted and powder coated every where except the pained surfaces and engine compartment.
It's all on stand still until I can get my hands on a welder. So it's all going to start happening at the end of winter. My goal is to get it ready for powder coat by the end of summer.

[Doc74]

Feel free man, but Ill warn you if I end up on a porn sight... I'm gonna kiss you!!

  Which pornsite would accept that ?!? passionate-werewolves.com ?   

The car is in a holding pattern. I stripped down the underbody, roof where the 3/4 top goes, engine compartment and wheel wells. I painted all the bare with por-15, mist coated the engine compartment with primer. I am ready to start tacking in new metal, filling pitted metal, and stiffing it as much as possible. I decided to stray away from the por-15 and after the new metal is I'm going to have the shell and doors media blasted and powder coated every where except the pained surfaces and engine compartment.
It's all on stand still until I can get my hands on a welder. So it's all going to start happening at the end of winter. My goal is to get it ready for powder coat by the end of summer.

Woah you've been busy, can't wait to see the pics !
What's the trouble with the welder ? A decent but small mig with a 50-50 mix of air and argon will do everything you'll need it for.
What's your budget ?

[wetfeetmi]

Try and air chisel with a dull dull chisel. You will have to be careful on sheet metal and wear hearing and eye protection. It is fast fast fast. It will leave most of the paint intact. makes sanding pretty easy.