Painting the inside of a tranny

[pfrederi 17,886]

Had a BFO today...(Blinding Flash of the Obvious)  Gear trannys frequently have a lot of rust inside. Over time just condensation can rust the inside of the tranny housing especially if it sits for long periods and the oil drains down.  Working on a Sunstrand transaxle right now and realized all the Sunstrand transaxle housings are coated on the inside.  Not sure if it is paint or what it is an ugly shade of orange.  Never found any rust on the inside of the several transaxles I have been into. 

 

Later project this winter is to fix a sick 8 speed.  I was wondering if I should paint the inside??  Also wonder what paint would hold up to a lifetime of gear oil on it.

[WHX?? 49,175]

Eastwood has this product

https://www.eastwood.com/glyptal-red-brush-on-1-qt.html

 

They're not exactly giving it away tho...'course if a guy could get maybe two or three trannys or maybe a engine or base pans out of a quart?

Couple of (vintage) motors I've cracked open had this in them.

I don't think its necessary in manuals but if a fella really wants  do it right?? 

Or has a situation where condensation might be a problem?

Might be best off doing regular oil changes??  

 

This or a similar product is probably what's inside the hydros for better oil return to sump.

Edited December 10, 2018 by WHX21
bad link

[Ed Kennell 38,682]

 Glyptal is what we used to coat all our oil filled adjustable blade hubs and servos in the hydro turbines.

[new2horses 287]

Paul,

 Like Ed and Jim said Glyptal or red insulating enamel by a generic name. Your NAPA store might be able to get it if not most any electrical supply store. It's been used for a very long time in motors, engines, gearboxes and machinery of most all types. 

[Sarge 3,463]

I believe the original coating was a type of Glyptal or a high solids enamel with a stabilizer. The trick to the interior coatings is they have to withstand being submerged in various types of oils - including mineral oil. Use the wrong coating with the wrong type of acidic oil and you've got a problem. Years ago we used a similar product to coat the interiors of transmissions and engines for the race cars, can't remember the name of the stuff for life of me, but it did have to be hot cured at around 200*F for an hour and stunk something fierce. We had an old house stove that got wheels mounted to it - the thing was hooked to the welder's drop cord and pushed outside in the open to cure that coating, otherwise, you just about couldn't breathe in the shop. Brush on only, don't think you could spray the stuff as it had some sort of acid-base to make it adhere properly. I do remember a serious number of health warnings on the label, doubt the stuff is even available now but it sure did stick. You could not remove it without seriously damaging the metal surface, it really ate into aluminum and iron. Areas that had internal bearings and were faced off for thrust washers required a lot of care not to paint them, I made that mistake once and that surface had to be re-machined. It worked really well, though - oils would run down it back to the pan very quickly and I doubt any of those parts have corroded to this day if they are still around.

 

Sarge

[oliver2-44 9,872]

The red Glyptal would be a great product for the inside of Tranny's. As mentioned above we used it on motors al electrical insulating paint and inside gearboxes at the power plants.

The challenge on an existing gearbox is to get all the oil that has soaked into the castiron pores out before you put the glyptal on.  I'v thought about taking the trank case and putting the halves faces down on my as grill and bake it out at 3300-400 degrees for a while.  Kind of like grilling a set of ribs

[ebinmaine 68,404]

4 hours ago, oliver2-44 said:

Kind of like grilling a set of ribs

I wonder which would smell better...

 

[oliver2-44 9,872]

@ebinmaine there no question which would smell or taste better. BBQ ribs are one of my favorites. OK I’m off topic

[bc.gold 3,403]

Foundry castings are shaken out to remove core sand, quality castings are painted to trap small particles of sand that may dislodge at a later date.

 

Most name brand manufactures require the inside of a casting be painted, not sure what they use but its definitely not your off the shelf paint found at Marshall Wells.

[ebinmaine 68,404]

1 hour ago, oliver2-44 said:

@ebinmaine there no question which would smell or taste better. BBQ ribs are one of my favorites. OK I’m off topic

That off topic was on me....

 

Seriously though it seems as though a barbecue grill would work pretty well to bake the oils out of a casting

[Sarge 3,463]

I have an old Char-Broil grill sitting outside near the work area for that specific purpose - I'd never want to cook in it again since it's been used to pre-heat parts prior to welding, baking oil/contamination out of aluminum castings and a whole other slew of things. Pretty nasty inside now as it's been pushed to 550*F to cook some certain oily parts for a job a guy brought over. Stunk up the whole neighborhood, but it worked great. Enough to wreck anyone's appetite when you cook heavy gear oils, lol...

Sarge

[The Tuul Crib 7,337]

Wonder how it would work under the mower deck? Has anyone ever tried it?

[bc.gold 3,403]

14 minutes ago, The Tool Crib said:

Wonder how it would work under the mower deck? Has anyone ever tried it?

The Glyptal 1201 is a red, alkyd resin enamel paint that comes in a 1 gal pail. The general purpose paint can be thinned for spray applications and works well as a sealer for screws, pipes, and hydraulic fluid chambers

Glyptal 1201 Features:

• Resin Type: Alkyd Enamel
• Color: Red
• Primary Color: Red
• Finish: Low Gloss
• Dry Time: 2h
• Application Method: Brush, Spray, Dip
• Container Type: Pail
• Container Size: 1gal
• Resistance Properties: Water Resistant, Heat Resistant, Arc Resistant, Chemical Resistant
• Quick-Drying (Yes/No): Yes
• VOCs Content: 3.98lb/gal
• Applications: Treatment of Coils And Armatures, Internal Coatings for Engines, General Plant Maintenance, Primer and Finish for Motor, Generator and Transfer Housings, Anti-Moisture Coating on Thermostat, Water Cooler, and Truck Control Parts, Sealer for Pipe and Stud

Glyptal 1201 Specifications:

• Meets requirements of MIL-E-22118
• Flexibility is far superior to competitive red sealers on both backed and air-dried films. 1201 can take rugged impact
• Water Resistance is excellent
• Prolonged aging doesn't crack 1201's film, leaves no place for destructive agents to get in
• Fast drying 1201 is tack-free in about 30 minutes at room temperature, can be baked to a beautiful smooth finish
• Heat Resistance. 1201 has got it, can withstand continuous 135°C temperature for months
• Prolonged Heat. After 3700 hours at 35°C, there is no change in dielectric strength
• Toughness. High-gloss paints have a tender film. 1201 has a low-gloss finish, designed for great resistance to abrasion
• Adhesion. 1201 hangs on, stays where it's put-on metals, ceramic, porcelain, concrete, fibers and wood
• Dielectric strength is rated at 1500 volts per mil, permits thinner coating than most competitive paints
• Arc Resistance, even with air-dried films, is 480 seconds

[pfrederi 17,886]

Way too much work/$$  My horses all live inside and i will not be around long enough for the painting to make a big difference.  Thanks for all the comments.

[Sarge 3,463]

Hmm, never read the complete specs on 1201, thanks for that. I think we may have stumbled upon a truly good deck coating, among other things. Seems as though there is no UV resistance, but I'll have to read further. The insulating properties and dielectric strength is impressive - with those numbers, it should survive a long time on a mowing deck among other things.

 

Sarge