TheSamba.com :: View topic - Is paint thinner safe to use on our aluminum cases?

Tue Aug 28, 2012 3:05 pm

I've been trying to clean my case for a rebuild for a while now, and it's proven to be a true pain. There is a lot of ?carbon? buildup that has beaten all other standard cleaning methods short of physically scraping it off with picks.

Today I was messing with some paint thinner for the first time and noticed the smell. I was taken straight back to a shop I once worked in, not knowing what fluid was used in the parts washer...

So my question is, is paint thinner safe for the case? As in, it's not going to eat it away. I need to get rid of the buildup and meticulously scraping it away is getting old, real fast! Any help?

Tue Aug 28, 2012 3:25 pm

BUSLUVR42 wrote: I've been trying to clean my case for a rebuild for a while now, and it's proven to be a true pain. There is a lot of ?carbon? buildup that has beaten all other standard cleaning methods short of physically scraping it off with picks.

Today I was messing with some paint thinner for the first time and noticed the smell. I was taken straight back to a shop I once worked in, not knowing what fluid was used in the parts washer...

So my question is, is paint thinner safe for the case? As in, it's not going to eat it away. I need to get rid of the buildup and meticulously scraping it away is getting old, real fast! Any help?

Paint thinner? as in Mineral Spirits?

That is what I use in my wash tank! My local oil supplier sells it for around $5.00 a gallon but I make it last at least a year or more. It will not hurt the case at all. I have also used aircraft paint stripper when I get hold of one that was painted.

Wire brushing by hand, or drill, pressure washing, scraping by hand all work too. Oven cleaner gets real bad crud, but will discolor the metal.

Glass beads, or walnut hulls work best!

Tue Aug 28, 2012 4:15 pm

Paint thinner won't eat aluminum but it'll sure mess with you, read the label and follow the safety precautions carefully.
MrJel adds some good options but I personally disagree with the use of glass beads inside an engine, embedded particles come loose later and contaminate the oil, same with walnut if it's used in a non dedicated blast cabinet that may contain remnants of other media.
I like Simple green for carbon and shellac, even better if it's heated slightly (check thier website for max temps), if all else fails aluminum wheel cleaner is magical for a final cleanup.

Tue Aug 28, 2012 5:29 pm

what about kerosene?

Tue Aug 28, 2012 6:38 pm

TheLoren wrote: what about kerosene?

K1 is too "oily" but it will work. Of mineral spirits, K1, and gasoline, mineral spirits are the least explosive. Gasoline is really a no-no for many reasons, but I have had to use it in the field.

I am kind of used to spirits but if I stay in the tank too long, I do notice some tingling. Gloves stop that. If the smell gets you, most hardware stores/building stores sell the low odor stuff, but it is a bit costly.

As far as blasting, I was speaking outer case crud. Blasting inside ain't good (soda may be an exception, I've not tried that). Careful use of the media and duct tape can make the case shine. After ANY blasting or chemical cleaning, a good pressure washing is a must. Coin-op car wash if you don't have your own.

One day, I will own an automatic pressure washer! I designed and built a system for paint lines, just never set up my own!

Tue Aug 28, 2012 8:49 pm

Spend 50 bucks and take it to machine shop and have it done properly. Blasting is out of the question. Do you really want to take a chance of any media making it's way into your rebuilt engine? You can spend days with every over the counter grease solvent trying to remove the crap in every nook and cranny. Or you can let a pro with a professional machine do it correctly.

Tue Aug 28, 2012 8:57 pm

don't blast it. You will never be able to find all the beads. Take it to a transmission shop or a machine shop and let them clean it. Then you clean it again when you get home.

Tue Aug 28, 2012 9:08 pm

Hoody wrote: Spend 50 bucks and take it to machine shop and have it done properly.

That's the thing, I have! Whatever this is, it's a nightmare. The machine shop got a good layer of grime off, but that was about it. I've talked to several people locally and pretty got the same reply every time, "have fun!". I've been able to slowly scrape off, for the lack of better terms, baked on crap, and then finish up with simple green, but this is taking forever.

The history of the engine with 70k, that I have concluded from tear down, was that it was ran too hot and the oil never changed... who knows if any additives were put in. This mystery stuff almost resembles coke in hardness, texture and appearance, but why it would be inside the case is beyond me.

I have had someone locally suggest dry ice blasting and there is a guy in town that can do it. Any opinions on this?

Tue Aug 28, 2012 10:55 pm

Try to find someone who hot tanks aluminam.

Wed Aug 29, 2012 4:55 am

super clean will do it. just be VERY VERY careful, as it can eat up the case. dont let it sit in a tub of it over night. i would let it sit on there for no more than 10 or so minutes, and flush with water.

don't use the purple power bullshit. castrol super clean. that stuff is amazing....

here is a demo i did

http://www.thesamba.com/vw/forum/viewtopic.php?t=480560&highlight=super+clean