Sail Boat Parts

[Guest]

Have a guy cleaning his parts for me to coat. This is an older boat. They are aluminum but are they like a pot metal? These two parts are what is called the escape hatch ( as long as you are a small person or down with the ship I guess ) and he has some more parts also as he gets them off the boat.
I was going to treat them with the aluminum treatment and then use the zinc rich primer and then the wet white by PBTP (good salt test on it) Any thing I need to watch out for or don't really need to do? This boat spends about 6 months in salt water and the other 6 here in fresh water.

[Smashing]

Re: Sail Boat Parts

Wait a minute -I thought zinc was not recommended for Aluminum?? I believe you said it HD!

[rbroker]

Re: Sail Boat Parts

Whats pot metal?

[Auto-Cycle PC]

Re: Sail Boat Parts

You ever heard of pot luck dinner? Same principal goes here a bunch of different crappy metals all melted together and cast into parts.

[Guest]

Re: Sail Boat Parts

Pot metal is also called white metal. It is a very low grade of metal. They started using it during WWII on cars because of the metal shortage. It is made up of different metals (aluminum, metal slag (or what ever)) that they could get to stick together. It was never always the same formula. But I have coated it before. It has a very low melting point and is brittle. Platting it is very costly as it involves so much preparation to plate. Time consuming. When it is stripped, it will start to corrode as soon as it hits the atmosphere.

[Guest]

Re: Sail Boat Parts

Time to do some searching I guess?

I found this. Page 2 has good info. Might be helpfull.
http://www.diggerspecialties.com/docume ... 4.08v5.pdf

This is what the company Hadco uses on their aluminum products.
HOUSING: Aluminum parts have zinc-rich primer and thermoset powdercoat for durability. Faceplates are color-impregnated. Die-cast aluminum back box contains less than 0.3% copper to prevent corrosion in concrete or masonry applications. Die-cast aluminum trim contains less than 0.3% copper to resist corrosion. (Note: Flange not included with CB100 fixture.). Thermal Protection device is required for installations in drywall, plaster, wood or other non-masonry materials.
FINISH: Thermoset polyester powdercoat is electrostatically applied after a five-stage conversion cleaning process and bonded by heat fusion thermosetting. Zinc-rich primer and thermoset powdercoat for durability.

This product also uses the Zinc primer

http://www.cabelas.com/prod-1/0055159019982a.shtml

So looks like its ok to use? I think also I have seen it used on aluminum bike wheels that someone was doing on maybe EW forum or this one. Its been a while. I also have this that I use for aluminum. http://www.liquiguard.com/liquiguardPCAL.htm

[Smashing]

Re: Sail Boat Parts

good info - I'm glad I brought it up. Looks like the KL is the way to go...

[Guest]

Re: Sail Boat Parts

I just talked to my Tiger powder rep (who has also owned his own pc biz for 15 yrs) and he says not to use the zinc-rich on aluminum.
His explanation:
Zinc is sacraficial to steel and will protect the steel from oxidizing (rusting).
Auminum is sacraficial to zinc. Zinc on aluminum will cause the aluminum to prematurely fail before the zinc.
He uses zinc-free on everything. He can't find any proof that zinc-rich provides any better protection than the zinc-free. He also mentioned that the zinc free is cheaper cost wise. The zinc-free has a lower specific gravity, so more coverge for your buck.

Just passing along some info.

What were you trying to say here? "Zinc on aluminum will cause the aluminum to prematurely fail before the zinc." Are you saying the zinc will cause the aluminum to fail? Just checking?

So what your man is saying is to use the reg primer and I guess its OK to treat the aluminum with the aluminum Liquiguard and then primer and then coat. I really don't know how many of you use the Liquiguard? From what I read it gives me just a little more protection from the start and I bought it for mainly using on boat parts for a little help on cover my butt a little longer
What you think?

[Guest]

Re: Sail Boat Parts

I just talked to my Tiger powder rep (who has also owned his own pc biz for 15 yrs) and he says not to use the zinc-rich on aluminum.
His explanation:
Zinc is sacraficial to steel and will protect the steel from oxidizing (rusting).
Auminum is sacraficial to zinc. Zinc on aluminum will cause the aluminum to prematurely fail before the zinc.
He uses zinc-free on everything. He can't find any proof that zinc-rich provides any better protection than the zinc-free. He also mentioned that the zinc free is cheaper cost wise. The zinc-free has a lower specific gravity, so more coverge for your buck.

Just passing along some info.

What were you trying to say here? "Zinc on aluminum will cause the aluminum to prematurely fail before the zinc." Are you saying the zinc will cause the aluminum to fail? Just checking?

Yup, that's what he said

So what your man is saying is to use the reg primer and I guess its OK to treat the aluminum with the aluminum Liquiguard and then primer and then coat. I really don't know how many of you use the Liquiguard? From what I read it gives me just a little more protection from the start and I bought it for mainly using on boat parts for a little help on cover my butt a little longer
What you think?

He uses zinc-free on everything. He can't find any proof that zinc-rich provides any better protection than the zinc-free. He also mentioned that the zinc free is cheaper cost wise. The zinc-free has a lower specific gravity, so more coverge for your buck.
Can't comment on the Liquigard, have not used it.

Thanks for the update. Have a good one.

[Guest]

Re: Sail Boat Parts

Update

Stripped all the powder off the bigger part and then the man bought me the paint and I painted the both of them. The small part over the powder and the large part over the raw. This crap that Hatteras had made was worse that pot metal made in the 30's. After I pulled it out of the strip tank I say all the holes and evey inperfection that was causing all the problems. Some how this part had been run through another process that filled in all the inperfections.

Well the parts are done and I got paid. I guess I ended up a 1 cent per min or 1/4 cent. No more coating this crap. I will paint it.