mule blasting

[major519]

I know that bits and pieces of my query have been covered here and there on the Forum but I would like some clear and concise opinions from experienced Mule restorers.
As I anticipate restoring my Mule, I am trying to do my research regarding paint preparation.
I know that I have to degrease my parts and then strip in some manner. What methods are guys using? I was thinking that soda blast or walnut would be the best.
And I am thinking that paint prep would consist of the application of zinc chromate primer or a self etching primer for aluminum.
Any thoughts on this?

[Chuck W.]

yes and yes!

We tried sand blasting, but it leaves the surface too rough. Now, we use soda blasting and it leaves the deck slick. A good cleaning with laquer thinner and some etching primer and you should be ready to paint. Maybe Rod will jump in and give you his tricks, he's the body and paint side of our restoration business.

[Rod]

When I degrease, I use a 50/50 mixture of Purple Degreaser and Simple Green. I spray the mixture onto the mule using either a 1 or 2 gallon garden sprayer. I allow the degreaser to work a bit and then pressure wash. Depending on how tought the grease/dirt mixture is, I may need to to this 3 or 4 times to get the mule squeaky clean.

Years ago, when we statred restoring mules, I was using a local sand blaster who was using a finer grit media in his blasting eqipment. This media was providing us with a good finish on the mules. Then my sand blaster changed to a rougher grit media and the blasting was leaving a rough texture on the mule deck. So, I had the blaster to start soda blasting the mules. While it cost a bit more, the sode leaves the mule with a smooth finish.

As chuck said, after blowing out the blasting media, I usually wipe the mule down with Lacquer Thinner.

Here is the info on the Zinc Chromate Primer that I use. If you search here on the G, you will see meany pictures of mules where I have used this primer on the base metal.

- The yellow Zinc Chromate Primer is a 2 part (the main primer and the activator).
- The mixture is a 1 to 1 mixture.
- Once mixed it must be used or it sets up. Only mix what you need.
- No thinning necessary.
- Use only a light coat, do not use a heavy coat.
- I have used it on steel and aluminum.
- Apply any good body filler on top of the zinc Chromate primer. the filler actually adheres to the primer better than it does to the bare metal.

The primer is made by Matthews Paint Company, Pleasant Prairie, Michigan, 53158. Phone 262-947-0700

For the gallon cans =

Part 1 is called the "Undercoat, Part # 74 734SP, Metal Pretreatment"

Part 2 is called the "Catalyst, Part # 74 735SP, Activator"

Try this URL for info - http://www.ppg.com/COATINGS/MATTHEWSPAI ... fault.aspx

I believe any Auto paint store which carries the PPG brand of paint can get the Matthews Primer. I purchaed my Zinc Chromate primer from a local independent auto paint store here in town.

To the best of my knowledge, none of the 15 or so of the mules I have painted this way have ever had the paint flake off.

Hope this helps.

[major519]

Thanks Rod
As I am starting to think about my mule resto, I have some other considerations to ask about.
My mule has pretty decent paint on the undercarriage (aluminum components like axles, trans etc), although it does have some paint chips etc. I am really considering not blasting these areas bare as it really does not need to go that far... The deck underside looks good as well but the deck topside has many layers and paint on it and generally looks like crap. I at least would like to soda blast this.
Now, I also have to do mechanical work as I have all the typical leaky gaskets etc and need new boots. Would you go ahead and do all the seals, gaskets, boots and misc mechanicals first and then paint, or would you simply degrease everything, paint and then tear into the mechanicals etc???
I am guessing that the first option would probably be the best although some items like boots ect would require masking.
What is Chuck and your usual order of operations concerning a mule rebuild?

[Chuck W.]

Almost all the mules we have done are as you described, the running gear and underside of the deck is in pretty good shape. I usually give the mule a good pressure washing before I do the mechanical work. While I've got the mule up on the work stand, I may go over the frame tubes and axle housings with a wire brush on an angle grinder to get rid of any loose paint, etc. Once the mechanicals are complete, it goes to Rod for prep and paint. This usually starts with powder blasting the top and sides of the deck, the rails, the foot basket, engine guard and wheels. Next is a good degreasing and pressure washing and then primer. Any body work is done at this point, and the deck may get a second coat of primer, depending on how much work was done. The mule is lifted about 6-7 feet off the ground and the wheels removed. The rubber parts are masked, including both sides of the tires. Once the underside has been given a good coat of paint, the wheels are painted and installed, and the mule lowered to the ground, then the top side is given a coat of paint. The paint is left to dry and harden for at least a week before the paint mask stencils are applied and the markings are painted. That's it in a nutshell. There have been a few that were completely torn apart, the individual components cleaned, repaired and painted, and then after the final assembly, the completed mule was painted again as described above.

This is one that we did for a customer that turned out really nice. A lot of work went into this mule, but it was a show winner after we got finished.

[major519]

Thanks a bunch Chuck.

I have been restoring MVs for about 15 years, everything from jeeps to heavy armour. I have pulled stuff right apart, right downt to every last nut and bolt and have also done "quick and dirty" restorations that are essentially mechancials and a repaint.
As my mule is in such decent shape, I agree that the "quick and dirty" approach will be sufficient to have a show quality vehicle. I always go through the mechanicals very thoroughly at the very least. I will be mounting new tires so I will have the opportunity to blast up and paint my dismounted rims off the vehicle.
Do the "Jeep Police" criticise the painting over of nuts and fasteners etc?

[Austringer]

On a mule, not really, just can't stand to see tie rod boots, axle boots (any rubber), and cotter pins painted over. Oh, and tires, take the time and tape stuff off.

[major519]

Well Jason, that was kind of my point exactly. I will make sure all the rubbers are thoroughly taped off, I hate overspray on things that shouldn't be painted as well?While we are on topic, has anyone ever produced the complete "book of the M274 mule"?
I am thinking a Guidebook similar to those done for MBs and GPWs...or even a restorer guide to....

[Austringer]

That's actually a good idea. I know mostly know very early straight M274 (best ones made) but I am not that familiar with the later ones (except the A5s, which I hate today, I've owned about 17 in the past 15 years). I'd be glad to do the early M274 and early M274 RR mules.

Jason

[Austringer]

Glad to hear you have new tires, hope they are the correct "balloon" style and not the, in my opinion, hideous looking straight walled tire. They just bug me and don't look right. I'm glad there is at least a new tire being made since the correct style is discontinued, at least for now.

Jason

[Dave M38A1]

Some great information on this forum. Thanks.
Questions on priming and painting.
Do you put the paint (Gillispe,etc.) directly on the Zinc Chromate? Or is an intermediate or
sealer coat needed?
Pulled the foot basket, engine guard, and fuel tank.
While I have the engine out for fuel pump and carb replacement and engine cleaning (removing
grass clippings and rats nests) I might as well clean up the bed and repaint.
Considering building a test stand for the running the engine.

I found some ultra fine sand that a friend who does a lot of blasting says will work well.
I'll give it a try, I have the sand blaster.

Thanks,

Dave

[Rod]

Dave,

Yes I apply the Gillispe paint directly to the Zinc Chromate. Just make sure to wipe down before painting as I described in my post above.

[Dave M38A1]

Good info. I really didn't want a heavy build up of primers.
Got the Gillespie USMC Green (24052). Just need to get the Zinc Chromate.

Thanks for all the information.


Dave