Paint advice

Quote:

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Originally Posted by The ho har's

gal should be weathered or a good etch, use a two pack paint with the matching undercoat

HoHar

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I've also heard you can wipe new gal clean with vinegar to 'neutralise' it for painting............if you can't wait for weathering.

Does anyone know what the residue is on fresh gal ??

yes thinners probably right...

Gal Tubing has an oily type film..thinners/prep-sol/grease will remove it..

ho har

Just to clear this thread up.
LandyAndys neat trailer was built using "Duragal" RHS which is different to steel that has been hot dip galvanized post fabrication - despite similar processes.

-Hot dip galvanizing is a very thick surface coating mechanically bonded to the steel surface.

-Duragal is a relatively thin but very even coating applied post seam weld to the steel sections.

Hot dipped gal will stand up to stone chips very well, duragal not so well. And as Andy mentioned where welds are made on the Duragal those weld areas need protection. They rust infront of your eyes up this way!!!

The white residue on freshly hot dip galvanized structures is mostly ash from the zinc tank. As has been mentioned this can be cleaned with a light acid wash like vinegar. There is some contention on whether hot dipped galvanized surfaces should be over-painted. Arguably by its nature a thick hot dip zinc coating is "self healing" which "works" best when not over coated.

To answer the original question, its sounds like you did the right things Andy. Clean, etch prime and overcoat. Essentially the only way to combat stone chips is having a very thick durable coating that is etched into the base metal. So either touch up after a quick clean and put up with stone chips or its time to grind back to metal - reprep and try a different top coat system? Two pack epoxy systems can be very hardy but are still dependent on their ability to etch into the base steel.

Steve

Quote:

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Originally Posted by roverrescue

Just to clear this thread up.
LandyAndys neat trailer was built using "Duragal" RHS which is different to steel that has been hot dip galvanized post fabrication - despite similar processes.

-Hot dip galvanizing is a very thick surface coating mechanically bonded to the steel surface.

-Duragal is a relatively thin but very even coating applied post seam weld to the steel sections.

Hot dipped gal will stand up to stone chips very well, duragal not so well. And as Andy mentioned where welds are made on the Duragal those weld areas need protection. They rust infront of your eyes up this way!!!

The white residue on freshly hot dip galvanized structures is mostly ash from the zinc tank. As has been mentioned this can be cleaned with a light acid wash like vinegar. There is some contention on whether hot dipped galvanized surfaces should be over-painted. Arguably by its nature a thick hot dip zinc coating is "self healing" which "works" best when not over coated.

To answer the original question, its sounds like you did the right things Andy. Clean, etch prime and overcoat. Essentially the only way to combat stone chips is having a very thick durable coating that is etched into the base metal. So either touch up after a quick clean and put up with stone chips or its time to grind back to metal - reprep and try a different top coat system? Two pack epoxy systems can be very hardy but are still dependent on their ability to etch into the base steel.

Steve

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Thanks Steve
Exactly the sort of info Im looking for.
Thinking areas that were rock blasted,wire wheel go again,may even consider that ute liner style product on the leading faces.
When finished there will be a rock guard on the D2 to help protect it too.
Where Ive been welding I will tread the areas the same then re-spray all the undamaged/protected areas with the top coats again.
Andrew

If the trailer was unpainted then I would suggest to give a coat of POT15 primer and when it is tacky then apply the finish coat.
POR15 will never come out but the premier it is not UV reistant.
I have tested it on steel yachts and it is one of the best products available.