Just had a new garage built. Contractor used "pre-primed" striated cedar shingles. I thought "great, one less coat to do". WRONG. Used light grey Sherwin Williams Super Paint- exterior latex satin finish. Had horrible tannin bleed through.

Then I covered with a coat of Zinsser Bulls Eye 1-2-3 Int/Ext Primer Sealer Stain-Killer(water clean-up). Looked OK, so the next day I put a top coat of the Sherwin Williams Super Paint. A week later I had horrible tannin bleed-through again!

Question: What will really work to keep the tannin from bleeding through?

Should I use BIN shellac based primer over all of the siding or just spot prime with it? Or not use that at all?

What about Zinsser Cover Stain High Hide Oil-base Primer Sealer/Stain Killer over the entire siding? (Either alone, or after spot priming with BIN shellac-based primer?

Many thanks for any help I can get, Chuck

 

I usually use SWP's A-100 oil base primer on raw cedar. Apply a good solid coat of primer, let dry a few days and then you should be able to top coat with latex.

I don't remember ever running across pre primed cedar but the method should be the same although I'm a little hesitant to recomend oil base over 3 coats of latex. Go back to SWP and explain the situation and they should be able to help you further.

 

NO ON THE BIN. It is very quick dry, and absolutly not for exterior use. It will peel and flake at the very hint of expansion and contraction.

A-100 exterior OIL primer from SW would have done the trick. The problem now is that you have painted wood.

Excuse my french, but tannin bleed can be a real bit**. Its been a while since I dealt with it, but ask the manager. You may even call the 800 # on the back of your paint can. Ask for a product specialist and describe problem. They may have some solutions for you.

good luck

 

Thank you very much for the advise.
The official response from the Sherwin Williams "Ask the expert" email help site at SW was:

"Tannins generally are water sensitive and when a water based coating is
applied will draw out the tannins. We suggest a long drying alkyd coating
like our A-100 Alkyd Primer. Once the primer has dried apply your latex
topcoat."
I will give it a go and pray for the best.

Chuck

 

Chuck

Was the SWP "expert" aware that you had already applied 3 coats of latex?

 

He should have been, since I merely copied and pasted my problem from this site. I also went to the local SWP store. They suggested I should give the present coats of latex more time to thouroughly cure before aplying the oil primer. Realistically, I have no other choice now since it is now getting consistently less than 40 deg. and I need greater than 50 deg. for the primer and then more time for that to dry.

I will give a follow-up in the spring.
Thanks everyone, Chuck

 

Well at least your siding is protected thru the winter. We expect to still be here in the spring so any time you need help .......... don't forget we have plenty of other topics to hopefully cover any diy advice you need.