(800) 853-2651
SHOP NOW

white stuff under paint on white-metal grill

B

bad sector

Member
Fixing up a Deutz-Fahr Dx-6.05 I sandblasted just so
lightly the front grill, and under the layers of paint there's
this white layer that could be some sort of primer or
some aluminum-rust as it were.

mvphoto102408.png


The image includes two copy-paste selections from
two images of the same typical area. Anybody familiar
with it? If it's just primer then no problem but if its
aluminum sweat then I'd like to prevent recurrence.

thanks for any wisdom
 
I am not familiar with that tractor at all. Sure looks like
aluminum surface corrosion or oxidation. I do not think
you will be able to hold a finish on that very well, at
least not long term. Not having any idea of the
magnification in the photo if that thinnest fin looking
part is at least an 1/8 inch thick I would blast it until it
was essentially bare aluminum unless during the
process you become concerned that to much material
is being removed. A photo from farther back of the
whole grill might help show what you are dealing with.
 
It looks like aluminum oxide. Basically same thing as rust, only different color. As used Red MN said, grit blast is best. You can also use an etching cleaner such as Bonderite C-IC 33 Aero, formerly Alumiprep 33. NAPA sells some similar aluminum brighteners and POR 15 has a similar metal prep that is a decent zinc phosphate coating for steel. POR 15 alloy prep might also be worth a shot.

You need a good primer with aluminum. Self etching or marine is where I'd start. The Bonderite link above is an Aircraft Spruce site that also has some rattle can primers for aluminum. They cater to the aviation industry, which tends to be fussy about using stuff that works.
 
(quoted from post at 16:43:21 02/12/23) I am not familiar with that tractor at all. Sure looks like
aluminum surface corrosion or oxidation. I do not think
you will be able to hold a finish on that very well, at
least not long term. Not having any idea of the
magnification in the photo if that thinnest fin looking
part is at least an 1/8 inch thick I would blast it until it
was essentially bare aluminum unless during the
process you become concerned that to much material
is being removed. A photo from farther back of the
whole grill might help show what you are dealing with.
Click to expand...

It's a 1991 German 4x4 with an air-cooled 6 hole diesel. That rib is about 3/16". The stuff became visible after 'investigative' blasting so presuming that the factory paint went on top of the appropriate primers, how would corrosion have gotten there in the first place?
 

You might try asking this in the Paint and Bodywork Forum the next forum down from this one in the Index. There might be someone who frequents that forum, but not this one, with some additional insight. A couple more pictures as has been suggested might help there, as well.

Paint and Bodywork
 

Thanks very much. I went and sandblasted the piece to stark naked but first I took a good look at the white stuff with a magnifying glass. What was
visible in the image was the residual that light blasting had not removed but there were a few specs that were still there and rather loose. They peeled off easy, something not typical of corrosion emulsions. I arrived at the conclusion that it was some kind of primer, maybe OEM. So THEN I went ahead and blasted it clean.
 
(quoted from post at 16:03:03 02/12/23)

It's a 1991 German 4x4 with an air-cooled 6 hole diesel. That rib is about 3/16". The stuff became visible after 'investigative' blasting so presuming that the factory paint went on top of the appropriate primers, how would corrosion have gotten there in the first place?
Click to expand...
he paint actually performed pretty well. Tractors see a lot of weather and chemicals over the years. The only addition that I would recommend over my previous post is the wash primer.

A paint system that lasted 30 years on cast aluminum did rather well. Moisture permeates paint. Eventually the corrosion inhibitors, if any, in the surface treatment and primer will be used up. The moisture works its way under the surface and you have seen the result. Any scratches, any thin spots in the paint, any defects at all will let the water in.
 
You must log in or register to reply here.
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top