Need Advice Painting Cast Aluminum- Prime, Paint & Clearcoat

[RTR]

Hey guys, I'm restoring a pedal tractor for my sons for Christmas. It is the more common Ertl model #404 that is in the style of an IH 86 series tractor. I've taken it all apart and have sandblasted all parts except the main body halves. Still have those to do. Not sure what this is made of but it appears to be cast of aluminum or pot metal. The rear axle housings seem to be cast out of aluminum.

My questions are about prepping, priming, painting, and clear coating the parts. I want to do it the correct way so the finish looks good and lasts for years. With the plastic parts, I'm going to clean them, scuff with a scotch-brite, use an adhesion promoter, then paint them semi-gloss black. With the steel parts (shafts & linkages) I'm bead blasting, spraying with sealer primer, spraying with filler primer, painting acrylic enamel with hardener, then clear coat.

What is the proper process for the cast aluminum and/or pot metal ? Planning on bead blasting those parts first and my thought was to use the same method as the steel parts. Didn't know if I needed to prep or use any other products with that type of metal.

 

[Tgrasher]

Looks like your prep work is really good. Self etching primer will give your colors good adhesion. If you want more sheen on the "sheet metal" after sandblasting, you might sand with 220 first, primer three coats, and then lightly sand before color coats.

 

[RTR]

Looks like your prep work is really good. Self etching primer will give your colors good adhesion. If you want more sheen on the "sheet metal" after sandblasting, you might sand with 220 first, primer three coats, and then lightly sand before color coats.

I thought about sanding the primer. Thank you. Didn't know if any specific primer or prep was required for that type of metal.

 

[Mike(NEOhio)]

If you sand blast the aluminum go easy. Back the nozzle away and move fast, don't linger on a spot. Just enough the take the old paint off.

 

[glennster]

use a baking soda blast media for aluminum, get primer on it immediately after blasting. harbor freight sell the soda blast in 50 lb bags. here is a link on aluminum prep from ppg. https://www.ppg.com/refinish/en-US/...res/pd-0115a-metal-surface-prep-bare-aluminum

 

[DoubleO7]

Not sure what this is made of but it appears to be cast of aluminum or pot metal. The rear axle housings seem to be cast out of aluminum.

If you have a postal scale or similarly accurate way to weigh the pieces, you could figure out if it is pot metal or aluminum.

Fill a straight wall container, maybe a drum? Deep enough to fully submerge part but not over flowing.
Mark water level without part. Then submerge the part and mark the new water level.
Container surface area x the displacement amount is the volume of the part.
You can multiply the volume in cubic inches by 0.258 to get weight in pounds for pot metal which is mostly zinc.

Now weight the part in question. If it is close to your calculations above, it is pot metal.

If it weighs less than half to one third of the above calculations, it is aluminum.

 

[RTR]

If you sand blast the aluminum go easy. Back the nozzle away and move fast, don't linger on a spot. Just enough the take the old paint off.

It’s glass beads in a cabinet

 

[Stephen Newell]

If it were me with a single stage paint I would skip the clear coat. A clear coat is really only good for a basecoat/clearcoat system. The acrylic enamel is enough alone. The most difficult part will be the decals. I would make clear photographs of it now before sandblasting. If you can't find someone to make the decals it can be reproduced by stenciling with paint. What looks like decals on this tractor is actually paint.

 

[RTR]

Here is the adhesion promoter and primer I bought to use after bead blasting the parts. I thought a good filler primer might be best so I can lay down 2-3 coats then sand it smooth before painting color. Probably using IH Red Ironguard paint from the dealer. Then I thought about clear coat over the paint. Also, was gonna paint the plastic parts semi-gloss black to freshen them up.

 

[Stephen Newell]

Here is the adhesion promoter and primer I bought to use after bead blasting the parts. I thought a good filler primer might be best so I can lay down 2-3 coats then sand it smooth before painting color. Probably using IH Red Ironguard paint from the dealer. Then I thought about clear coat over the paint. Also, was gonna paint the plastic parts semi-gloss black to freshen them up.

View attachment 89659
View attachment 89660

You might contact High Tech. Sometimes when you mix types of paint they are incompatible. There is a risk the Ironguard paint won't adhere well to the primer.

 

[10fingers]

Hey guys, I'm restoring a pedal tractor for my sons for Christmas. It is the more common Ertl model #404 that is in the style of an IH 86 series tractor. I've taken it all apart and have sandblasted all parts except the main body halves. Still have those to do. Not sure what this is made of but it appears to be cast of aluminum or pot metal. The rear axle housings seem to be cast out of aluminum.

My questions are about prepping, priming, painting, and clear coating the parts. I want to do it the correct way so the finish looks good and lasts for years. With the plastic parts, I'm going to clean them, scuff with a scotch-brite, use an adhesion promoter, then paint them semi-gloss black. With the steel parts (shafts & linkages) I'm bead blasting, spraying with sealer primer, spraying with filler primer, painting acrylic enamel with hardener, then clear coat.

What is the proper process for the cast aluminum and/or pot metal ? Planning on bead blasting those parts first and my thought was to use the same method as the steel parts. Didn't know if I needed to prep or use any other products with that type of metal.

View attachment 89178View attachment 89179View attachment 89180

When I worked in the body shops zinc chromate on metal followed up with a primer surfacer or sealer. A sealer was used for wet on wet eg, zinc then sealer then paint. All wet on wet ie, one coat after the other.