Fan/shroud blasting options/input

[sugarwood]

My '86 fan has oxidized. Not pretty.
Is it hard to remove the fan and housing for a better cleaning?

[/QUOTE][/QUOTE]

3) Gibbs Oil - Best stuff for restoring aluminum and magnesium. Spray it on and in a day, all the oxidation will be gone.

Does anyone have experience with Gibbs oil?
It magically removes the Magnesium pitting on the fan ?
I currently do not have plans for getting my fan plated or powder coated.

Gibbs Brand penetrant

[mhackney]

It's not hard to remove them at all. Do you have Wayne's book? Or Bentley? It took me about 15 minutes to remove the shroud and fan/alternator. I think I you could spray Gibbs or WD40 and use a scotchbrite pad to clean it up.

I'll be treating mine with Gibbs and that's all.

[sugarwood]

Originally Posted by mhackney

It's not hard to remove them at all. Do you have Wayne's book? Or Bentley? It took me about 15 minutes to remove the shroud and fan/alternator. I think I you could spray Gibbs or WD40 and use a scotchbrite pad to clean it up.

I'll be treating mine with Gibbs and that's all.

Yea, I have both. Neither inspired much confidence, as it was unclear once the alt. was partially removed.

Please post before/after photos of your Gibbs treatment.

[mhackney]

Will do on the photos.

The removal process really was straight forward. Your fan/shroud is not covered in grease like mine was so you'll likely have an even easier time.

[mhackney]

I just finished bead blasting the fan and the finish is perfect! I am trying to go for as-made with a little age look, not a highly polished or textured surface. The glass beads are quite mild but get into the pockets and remove the black oil and grime easily. I'm using a 1/4" tip at 60 PSI and it is reasonably fast. I might try increasing the air pressure for the larger shroud.

[Tippy]

What size/weight? Glass I used really was aggressive.

[mhackney]

This was a US Screen #70-140, a bit finer than what John Walker recommended but my local supplier recommended I try this.



I bought a 50# bag as that was the smallest but in a simple box with recovery you really only need 5-10#s

Here's a link to Potters grades: http://www.pottersbeads.com/LinkClick.aspx?fileticket=O43vEJ5TV84%3d&tabid=291&mid=1009

[mhackney]

This is the before and after bead blasting. This fine mesh bead is perfect to clean but not leave a textured or polished surface. If you need to remove paint, I think a courser material may be better.

There is a difference between glass bead and "glass". The later has sharp edges and would be more abrasive.

Before Blasting


After Blasting

[Tidybuoy]

Looks Great! I would have done my own if I still had my blast cabinet but that's been long gone.

[mhackney]

I treated the fan with Gibbs. The instructions say to wipe it on with a cloth. I decided to spray it on and use a paint brush to make sure all of the surfaces were wet. I then wiped it off with paper towels. It does not seem to change the color of the magnesium at all. The label claims that it leaves a thin waterproof protective film and that you can paint over it as soon as you wipe it off!



The fan is exactly the look I wanted. Now that I'm the owner I will keep up with things like this and not let it get as grimy as it was. The Gibbs is supposed to help so we'll see how it works and lasts!

[mhackney]

The plastic shroud that fits to the back of the alternator has 2 steel fins that are rusty. While I'm at it, I'm using rust remover on them. I might blast these too. You can't see these when everything is back together. I need to think about how to protect them. I might treat with Gibbs "just because" and see how that works.

[sugarwood]

I'm jealous.
I don't have a bead blaster, so I might just scrub it.
What grit of scotch brite should I use?

[mhackney]

You can get a portable unit like the one I posted on the 2nd page for $60 cheaper at HarborFreight (and they carry media too) and the media was less than $50. I used a big cardboard box on sawhorses with a 5gal bucket underneath to catch and reuse the media. I ended up buying the HF bench top unit on sale for $109 this morning and it comes with the gun too, assembled and ready to use. I plan to do a lot more blasting! I just finished the shroud posted above and it looks great, all of the clamps, screws, nuts, etc. This bead does not remove the plating if you stay back about 5" at 60PSI and the 1/4" tip.

[Tidybuoy]

Originally Posted by mhackney

I ended up buying the HF bench top unit on sale for $109 this morning and it comes with the gun too, assembled and ready to use. I plan to do a lot more blasting!

I used to have this unit and my advice is that you use the plastic film that goes on the glass viewing window. Maybe buy extra. When I ran out of that film and the existing film got cloudy, I eventually removed and in very short order the glass was so frosted I couldn't see a thing.

[sugarwood]

Abrasive Blast Cabinet

Unfortunately, that thing is too large for my garage and storage space.

[mhackney]

Then get the portable unit or a gun from HF and use a cardboard box. Google it, there are lots of plans on how to make good cabinet from cardboard. Or, the material the "Vote for me" signs are made of - coroplast - also makes a great box and you can usually find large enough sheets for free. The beauty is that it can be folded flat when done.

[mhackney]

On the Scotchbrite sugarwood, I used the grey (ultra fine) to remove the grease and begin the cleaning. The parts above in the "before" photos were cleaned with Scotchbrite grey pads and brake clean. Scotchbrite is not going to get stuff out of the pockets in the castings as you can see.

[Tippy]

That came out great!

[Fixer]

Usually you try soda first and when that's not doing it, switch to a more aggressive blast media. If not soda, you can try walnut shell..

What i would have done; would be to have used paint stripper to remove the "unknown paint". Aircraft stripper will take and paint off.

Brush it on, bag it in plastic, wait 12 hours and hose it off.

Next i would gently wet sand the fan with 240 gt ONLY in the BAD areas if there are any, quickly moving to finer 320, 400, 600 and so on. If the fan looks very good after paint removal simply go right to the buffing wheel. I cannot say as i don't have the fan in front of me.

Anyway, I would bring it to a nice polish and when i liked it I would clear coat it with real quality catalyzed urethane clear coat. But you could also use light oil as you wrote to keep it looking nice. But that requires continued maintenance. Clear coat can be bought in less glossy finish if you don't want it too shiney wet looking.

What you used looks great though but i still see some chips and scrapes.

[mhackney]

That's a reasonable approach The Fixer. I actually did remove the paint with stripper (shroud only, fan was not painted). I also consulted with a media supplier, took in my old cracked part and they showed me the results of several different media and I had tried walnut shell at home first. I did not want to sand as that certainly removes metal and that is not the look I was after, I simply wanted to clean the surface with as little metal removal as possible. I had the old part to experiment with. I also did not want to buff as that will leave a polished finish, I want more of an "in use" matte finish. The 70-140 media was perfect for that. I don't mind maintenance to get and keep the authentic look I was after.

I left the chips and scrapes there on purpose because they are "honest" - meaning this is how they are with use. I wanted clean and respectful. I perfectly understand the attraction to polished and especially those beautiful ceramic coated parts posted earlier. I want to keep this car authentic but if I were building/maintaining a more common car I would have gone the better than stock route. Maybe my next one!

cheers,
Michael