Undercoating removal?

[rmicroys]

Okay... I'm on a mission to get every last ounce of weight out of my '86 Jetta. I very may likely get a weight reduction in my car's class for next year. Currently we have to weigh in at 2250 with driver. I need to find 100lbs!!! The car currently weighs about 2050lb.

I'm starting with the removal of all the sound deadening and rust proofing. Other than a rigid scraper, a whole lot of hard work and skinned knuckles - is there any good way to get the underbody coating off? The rear trunk area sound deadening is coming off pretty easy. I'm just afraid that I'm going to be spending months taking off the underbody coating this winter! But at least the first race isn't until the end of April - I've got time on my side, as I've already started!

[racer_tim]

There was a similiar thread a few months back. Best thing I recall was dry ice, and a hammer. Working in small sections, let the dry ice freeze a certain section, then whack it with a hammer.

There were also some links on the old thread.

or you can loose 25 lbs, and only take off 75 from the car. Just kidding.



------------------
Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit (Bent)
http://linerud.myvnc.com/racing/index.html

[rmicroys]

Originally posted by racer_tim:
There was a similiar thread a few months back. Best thing I recall was dry ice, and a hammer. Working in small sections, let the dry ice freeze a certain section, then whack it with a hammer.

There were also some links on the old thread.

That's what i've heard - but for the undercoating? I know it's easy to use dry ice on the interior sound deadening, but how does one do it for the undercoating. Got anti-gravity dry ice?

I tried searching, I'll look again....

or you can loose 25 lbs, and only take off 75 from the car. Just kidding.

Well... That's the nice part. We already run 25lbs of balast to get to our 2250lb weight. I only weigh about 175 with gear... I could always try to lose 10-15lbs though!

I'd also like to get as much out of the car as possible, then I can ballast appropriately, and put the weight where I want it!

[This message has been edited by rmicroys (edited October 06, 2003).]

[bbp]

We used a propane torch and a scraper. If the interior is clean and free of coating, you can use the torch to heat the sheet metal on the inside, then get underneath and begin to scrape it off. The hot sheetmetal breaks the adhesion of the tar...comes right off. Be careful not to catch anything on fire... plastic, fuel lines, brakes lines, wire harnesses etc...

[joeg]

Liquid Nitrogen hooked up to a suitable wand gets the stuff real cold--supposedly.

Sounds like a real dangerous undertaking, however.

VW(s) have about the most thick and tenacious body shutz. You can also use aircraft stripper which will be very messy.

People sometimes hand cloth bags with dry ice
and hang them in the wheel wells.

You may want to consider a rotisserie to overcome the gravity issue!

[rmicroys]

A friend recommends NOT using aircraft stripper to get the thick stuff off - been there, did that, didn't work well for the effort and fumes. Maybe for the last cleaning to get the little tenacious bits but not the bulk of it. Everything I have heard that works for the underbody stuff is heat and a scraper. Propane torch on the inside, or a heat gun from the outside or inside and have at it with a rigid scraper. Either way. Long messy job. Thanks for the tips.

I'd love the rotisserie, but my garage/work area is in the burbs. I don't think all the people on my street would appriciate it if I had this thing on my driveway. This will be mostly done with me on my back lying on the cold garage floor all winter. At least it will be warm with the heat gun!

[SamITC85]

I am in the same boat for my G-Prod Scirocco. I have found that the torch and the chisel/scraper have worked the best, also a angle grinder and wire wheel does a great job, just be prepared to buy a lot of wheels.

------------------
Sam Rolfe
TBR Motorsports
#85 ITC VW Rabbit
#85 GP Scirocco on the way
#11 GP Scirocco on the way

[racer14itc]

I've tried it all on my VW Sciroccos, and here's what worked best for me: a 4-1/2" angle grinder with a knotted wire brush cup. Wear GOGGLES, FACE SHIELD, heavy jeans and shirt. When those little wire bristles do come off the cup (especially if you try to use it up to the nubs), they come off at a hundred mph!! They WILL stick in your face, leg, wherever so be protected.

The upside is it isn't as dangerous as chemical stripper, diesel fuel, dry ice (frost bite!) and MUCH, MUCH faster than a scraper. If you can't get a rotisserie, raise one side at a time using plenty of jackstands and go at it! If the car is completely stripped and empty, some folks I know have rolled the car on it side in the yard/driveway to get at the bottom easier.

Hope that helps.

MC
GP #14 VW Scirocco

[This message has been edited by racer14itc (edited October 06, 2003).]

[67ITB]

Rmicroys,

1. HEAT is your friend !!!! Flame or heat gun both work well
2. Do you have access to a lift ???? USE IT
3. Get as many different types of scrapers as you can find sizes, shapes, hardness…
4. Paint remover. I used this “Orange stuff” from Sears, It was in a spray can and would stick to the wheel wells of the car. Let it sit for 30 minutes and you could just scrape to the bare metal. CAUTION: it smells good…..BUT DON’T FORGET THE GLOVES you will notice a slight burning sensation on skin if you forget them.
5. Final clean up of the metal works with some diesel fuel to remove any “gum” and then use a wire wheel or a “flapper disc” on a rotary tool
6. Try to drag as many friends into this as you can, everybody can help scrape =) you provide the beer and the tools

I have done this to 3 Sciroccos and I try to weigh the stuff that comes off the car. You will NOT be able to get the 100 LBS you looking for, but should be able to get at least 10-15 LBS
Nothing was as depressing as the winter I spent like 2 days under the car on a cold concrete floor and only got 8 LBS

Good luck
Matt

[rmicroys]

Originally posted by 67ITB:
You will NOT be able to get the 100 LBS you looking for, but should be able to get at least 10-15 LBS
Nothing was as depressing as the winter I spent like 2 days under the car on a cold concrete floor and only got 8 LBS

Good luck
Matt

Oh gosh... I KNOW all that rust proofing doesn't weigh 100lbs... I have to get 10lbs here, 5 lbs there, etc, to get my 100lbs. It's going to be a lot of work, but oh well.. Maybe time to get a couple sets of Volk TE-37s and ditch the lumps of cast aluminum wheels that I have now. I know I should be able to find a few pounds at each corner on my wheels alone.

The problem is that I also want to add a couple tubes to the cage, and improve the stiffness - so that's just going to add more weight. Grrr... it's almost a lose-lose situation...

[67ITB]

rmicroys,
I don’t want you to take my post the wrong way, I have been known to spend hours just looking at a VW for places to remove weight.

If you work hard at it you can find every pound you need to remove. And its all legal.
I do this because I tip the scales at WELL OVER 200 lbs so rather than go on a diet, I will spend hours trying to find ounces.
As for adding the weight back in with roll cage bars. That is weight that YOU put in where YOU want it. That’s why we work so hard to take it out in the first place.
It’s a sad cycle that never ends but the beauty of it is that weight removal cost nothing but time….

Again good luck with your project
Matt