# might have a prob with rust



## Quaid? (Mar 13, 2009)

so we grinded the paint off of an entire old farmhouse with the paint shaver pro. the siding is ceder lap. we sanded everything smooth, including the rusty nail heads, so there was no more rust on them. primed everything with sherwin oil primer. after it cured, top coated with duration white. 2 weeks later i can see rust burning through on the nail heads. we pulled one of the nails out and there was rust all the way down the spike. any advice?


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## johnpaint (Sep 20, 2008)

You may need to back brush the siding to get the DTM to seal completly.


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## Quaid? (Mar 13, 2009)

we back brushed every coat


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## Metro M & L (Jul 21, 2009)

You may need to back brush the nail, all the way down the spike. LOL sorry it's really not funny. 

Just brain storming. Nail set all nails and then top coat them with bondo? I bet that would kill the rust!

Whenever I run into a stain I just cannot kill I turn to rustoleum dark grey or black.


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## TJ Paint (Jun 18, 2009)

Metro M & L said:


> You may need to back brush the nail, all the way down the spike. LOL sorry it's really not funny.
> 
> Just brain storming. Nail set all nails and then top coat them with bondo? I bet that would kill the rust!
> 
> Whenever I run into a stain I just cannot kill I turn to rustoleum dark grey or black.


so rustoleum would kill/seal stains for you? is that what you mean?


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## TJ Paint (Jun 18, 2009)

Quaid? said:


> so we grinded the paint off of an entire old farmhouse with the paint shaver pro. the siding is ceder lap. we sanded everything smooth, including the rusty nail heads, so there was no more rust on them. primed everything with sherwin oil primer. after it cured, top coated with duration white. 2 weeks later i can see rust burning through on the nail heads. we pulled one of the nails out and there was rust all the way down the spike. any advice?


on alot of the nails or just a few? if its only a few, i'd say just spot prime and try to touch it up since its fresh. if its the majority of the nails, I'm not sure what to tell you.


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## TJ Paint (Jun 18, 2009)

heres something i stumbled on, for what its worth:
source: http://www.paintstore.com/drpaint.php?mode=read&item=9996&returnName=Dr. Paint Directory&returnURL=drpaint.php%3Fpage

*Posted By * kevin *Question * What is the best primer or method to hold back rusty nail heads from coming through the top coats. *Answer * Hello,



Nail heads can rust and create spots on painted surfaces on your home. Using steel nails rather than galvanized nails causes this problem. 







Remove any stained paint around all nail heads by sanding the area or using a wire brush. Sand clear down to the nail head, then sand the nail head itself to remove the built-up rust.







Use a nail punch to countersink all nail heads approximately 1/8" below the wood surface.







Apply one even layer of rust inhibitive undercoat over the countersunk nail and the area around it.







After the area is primed, fill the countersunk hole with a good grade of putty or linseed oil putty. Allow 48 hours drying time for linseed oil putties before painting.



Dr. Paint


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## NACE (May 16, 2008)

Galvanized nails have a chemical reaction between zinc and tannins. Usually this results is a black spot around the nail. Stainless is the proper fastener for cedar or redwood. If the nails are steel, an alkyd rust inhibitive primer is needed. If they are galvanized, since alkyds react with zinc by supponification or zinc soap, a water based rust inhibitive primer should be used for spot priming. Did the grinding remove the zinc coating? If so, flash rusting will occur very quickly. Fast drying alkyds will not hold back rust for long. Unless the resin is a true phenolic alkyd, it should not be used on galvanized metal. Spot prime, fill with filler of choice, prime with proper primer, topcoat.


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## Quaid? (Mar 13, 2009)

thanks for the info. problem is im done with the house, so going back and countersinking all the nails, filling, prime and topcoat is a pretty big hit.


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