Mid- Engine Modified Sports

[wobblywalrus]

A paint system like you are thinking of using is very similar to the one used on my favorite dirt bike frame and swing arm a few years ago.  It works very well.  One good thing is the corrosion seems to be limited to areas where the paint is missing from the surface.  The rust does not seem to get under the coating near the break like what happens with other paint systems.

[manta22]

This is why I asked Neil, I did these for my Hurst shifter a while back and was thinking one might work for you?.

That is quite a shifter there, Mike. If I had a choice I would plate steel parts with electroless nickel but the passivated zinc will have to do.


Regards, Neil  Tucson, AZ

[tauruck]

Is that what we call Cadmium plating over here?

[manta22]

Mike;

No, cadmium plating is distinctly different from electroless nickel or zinc plating. There are so many restrictive regulations in place now that it is hard to find anyone doing cadmium. It's mostly military stuff and not really practical for guys like us.

Regards, Neil  Tucson, AZ

[jdincau]

Mike;

No, cadmium plating is distinctly different from electroless nickel or zinc plating. There are so many restrictive regulations in place now that it is hard to find anyone doing cadmium. It's mostly military stuff and not really practical for guys like us.

Regards, Neil  Tucson, AZ

It's a shame too because cad plating has the best salt corrosion resistance. All the steel parts on airplanes we built for the Navy were cad plated, baked, zinc chromate primed and painted with a catalyzed paint.
Jim, a lazy L retiree

[tauruck]

Gee, I'll be taking a bunch of stuff to the plater for cadmium at the end of the month.
http://www.teamplating.co.za/

Gary is going to do all the parts for the liner.


I learned something new "again".


Thanks guys.

[manta22]

I loaded up the  bare chassis on a trailer this morning and dropped it off at Prois Sandblasting in Tucson. This will prep it for priming and painting before all the aluminum panels go on and everything gets reassembled. They may get it finished on Friday but it will probably be Monday. I'm hoping our monsoon rains hold off until the primer goes on. I'll be prepping & priming some aluminum panels with zinc chromate epoxy in the next few days if the weather holds out. Doing this in one's driveway isn't as nice as a proper paint booth but ya gotta go with what ya got.

Regards, Neil  Tucson, AZ

[tauruck]

Neil, when I lived on a farm my neighbor Henry had a collection of Thunderbirds. His house was right on the road and he would spray paint cars in the driveway.
Not just any old paint mind you. Pearls and flake. His wife would stand on the dirt road to stop anyone getting near the property. Not difficult for her, she was a big girl.

[Finallygotit]

Doing this in one's driveway isn't as nice as a proper paint booth but ya gotta go with what ya got.

Look at it this way Neil, your outdoor lighting can't be matched by a paint booth.  And what's a little sand in the paint?  Pfffttt

[manta22]

The rain held off today so I was able to prime some of my aluminum chassis panels. I scuffed the surface with a fine 3M bristle brush in an angle grinder and wiped it down with denatured alcohol. The primer is a PTI zinc chromate two-part epoxy. I sprayed it with an el cheapo ($9.99 on sale at Harbor Freight) paint gun.

I bought a "1 gallon kit" from Aircraft Spruce but it turned out to be 1 gallon of primer and 1 gallon of hardener. I won't complain about that! The primer needs to be mixed 1:1 (convenient!) and then left standing for 10 to 20 minutes before spraying. It dries to the touch in about 30 minutes so the panels could be turned over to be primed on the back side without a long wait.

I should have my chassis back from the sandblaster on Monday and I'll prime it before topcoating it with the trick aerospace polyurethane.... if the monsoons cooperate.   

Regards, Neil  Tucson, AZ

[Milwaukee Midget]

Neil -

I know you're looking to have this prepped for a courtesy inspection during Speedweek - Will it be just the chassis, or will you have time to put the panels back into place?

Either way, I'm excited to see it.

 

Chris

[manta22]

Chris;

The panels that I just primed will be riveted in place and I'll re-assemble as much as I have time to complete by the time it's necessary to get it on the trailer. I'll probably rent a flatbed car hauler to take it up to Bonneville so it will be easier for the inspectors to see the underside, etc. Next year I'll use my enclosed Haulmark trailer.

I'm looking forward to seeing your cool mint green Midget, too!

Regards, Neil  Tucson, AZ

[tauruck]

Whenever I see zinc chromate I think "airplanes". Never had the opportunity to use it but hopefully one day soon.
The parts look good Neil. 

[manta22]

Mike;

Aluminum = zinc chromate. Airplanes or race cars.

Regards, Neil  Tucson, AZ

[manta22]

While waiting for my chassis to be finished at the sandblaster's shop, I've riveted a few things onto the bottom panels. To stiffen the bottom rear panel, I riveted on a titanium "hat section" using 1/8" (#4) CherryMax blind rivets. These are aluminum body/steel stem blind rivets that break the stem flush with their dome head and crimp a retaining ring around the stem to retain it under severe vibration. Since the main shear strength of a blind rivet is in its stem, having a stem fall out weakens it considerably-- another reason not to use hardware store pop rivets.

I also riveted the aluminum angle battery retaining brackets on to the bottom stressed panel. I used 1/8" Huck Unimatic blind rivets. These are A286 body & stem- a really strong stainless alloy. Unimatics also have a locked stem but they do require a special pulling head that stakes the lock ring into the stem before it breaks flush with the head. It is no fun to pull these by hand!

Here are a couple of pictures of the pieces I did today. Tomorrow I'll rivet the 10 lb fire bottle retainer on unless I hear from the sandblaster.

Regards, Neil  Tucson, AZ