bmw back to life project-need guidance

[omkar]

started project

hi guys

started the bmw this weekend. i have a question about the protective coat under the car.

im trying to take it off using an electric heat blower and a putty knife. but the stuff is really on there. so im now wondering if i could just thoroughly clean it an apply a coat of anti chip over it...in much the same way u could do with painting....

thanks for any help on this guys

 

[oz.]

There is a likelihood of the new stonechip reacting with the old. Also not clearing it away means that you're not revealing any rust that may be hidden under there.

Once you've removed most of the thickness and you still have a thin layer petrol or thinners works well at removing the last bit.

 

[omkar]

hmm.....i see....good point.

i have another question. its about the removal method.....i remember reading on this forum that a guy used a propane torch and a putty knife to remove undercoat.

is this way more efficient than a heat blower??

 

[oz.]

Effectively the same thing but the propane torch would be hotter. I'd imagine it makes the putty softer.
There comes a point when it becomes soft, a little hotter and it's sticky and difficult to remove. Finding the balance should be fairly easy

 

[omkar]

thanks for the info oz.

 

[demag]

I'd be very careful using the propane burner in case of fire, last thing you want especially if you're underneath it at the time.

 

[drjim]

The stuff you are removing will be the same as the underseal on my E21 track car. I started out with a hot air gun and scraper, then got annoyed and used a propane torch, then got more angry and hit it with a big wire brush on the grinder. Then I undersealed over the bits I'd removed and left the rest alone. If it hasn't got a rust hole showing it won't be rusty underneath. BMW did such a good job of the cars that removing it is an ordeal. Just a shame they didn't do the sill/floor join on E24's etc properly too!

 

[omkar]

thanks drjim.....i was questioning wether i should remove stuff that is obviously in good shape.......i just thought it had to be done.......

im really thankful....i think u saved me a couple weekends of frustration

 

[omkar]

oh...by the way.....what did u use to reseal the places u had removed?.....

as what oz said......stonechip MIGHT react with the old stuff.......

 

[drjim]

I painted over the bits of bare metal and sprayed dinitrol underseal over the top.

 

[Dr pepper]

Hi Omkar,

Great to see your keen with the project.
What gas do you have for your mig?, c02 works allthough I find car stuff much better with argon/c02, argon/c02 is usually only available on a contract thats the only problem, I found a supplier here that does smaller bottles non contract, might be a bit tricky over there, esp if you dinna speak the lingo.

 

[omkar]

actually.....over here in holland u buy the gas bottle. u can buy a 5, 10, 20 litre refillable bottle. when its empty i can just carry it in, pay 45 euro for the gas and i recieve a filled gas bottle.

i have a 10 litre argon/co2 bottle that was a package deal with the welder i bought. i think its a 25% co2 mix.......

 

[omkar]

hi guys....going to buy some sheet metal this weekend to work on the inner wheel arches. i also need to do some work on the sills.....

i dont need to replace anything......just cut and patch work.......

i need to ask...

does the inner wheel arch and the rest of the body use the same thickness of material.

and can anybody recommend to me what is a likely thickness material i should be looking to get.......i plan on cutting out round the holes and taking that material with me when i go to source my material.......but, i wanted to ask for some advice first...

appreciate any help guys. thanks