posted
OK, The signs came back! Last year I primed them with Zinsser H2o based and I believe I primed them below adequate temps but beside that, I had to put UMPTEEN coats on the friggin things to stop the bleeding through. I believe I am done with H2o based on cedar.
I have sanded them down to bare wood again except for the stained-blasted part (it looks great).
I am in need of a (preferred) oil based block out for cedar unless you have better advice. The H2o based had bubbles all over it that never bit into the grain. They were clean but, again, I believe my temps were too low.
Idealy, I want to put 2 coats of primer/block out/stain blocker on them on then paint them all the colors of the rainbow after that. They are 9 golf course signs that measure 2' x 3' each.
posted
We use Cabot's oil base primer for cedar. Most of the time one undercoat is all that's needed to block out the bleeding. Then we use two coats of acrylic latex paint for the finish coat.
-------------------- Jean Shimp Shimp Sign & Design Co. Jacksonville Beach, Fl Posts: 1266 | From: Jacksonville Beach, Fl. USA | Registered: Nov 1998
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posted
Corey, I do 50 or 60 sandblasted cedar signs every year, usually with Jay Cooke Primer. Once I had a bubble, due to a high moisture content, but that was it. Any of the darker colours in Acrylic Latex will usually cover the tannin stains, but I have to use 1-shot or Deka in the light colours
-------------------- Rodger MacMunn T.R. MacMunn & Sons C.P.207, Sharbot Lake, ON 613-279-1230 trmac@frontenac.net Posts: 472 | From: Sharbot Lake, Ontario | Registered: Nov 2003
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posted
a primer is a primer, oil baised primer is good thined on the first coat full strength on the second coat then or laytex top coat. also you migh think about a shelac based primer for the ulimate stain block!
good luck!
chris
-------------------- "We have been making house calls since 1992"
Chris Lovelady Vital Signs
NOW WITH 2 LOCATIONS! Tallahassee, Florida Thomasville, Ga.
posted
Hey Bill, I did not do any tests to determine the exact moisture content however it was clear kiln dried cedar and I live in the extremely dry climate of Alberta, Canada if that helps. When I primed them, it was about 32f with a warm air Chinook blowing in bringing the temps up to maybe 50f at the time.
posted
You can use either latex or alkyd (oil) top coats over any primer. My understanding is that primers have a flat finish which makes it easy for the top coat to "grab" onto it. You wouldn't want to put a latex top coat over a slick alkyd finish paint. There is no grabbing surface for the latex to stick to. I use latex paints for about 90% of our work. About the only time we use alkyd is for bleed problems with cedar or redwood.
-------------------- Jean Shimp Shimp Sign & Design Co. Jacksonville Beach, Fl Posts: 1266 | From: Jacksonville Beach, Fl. USA | Registered: Nov 1998
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posted
Just cause it says "kiln-dried" lumber don't necessarily mean it's ready to paint. The drying process takes the percentage of moisture content down to or below 19%. Once it leaves the kiln, it could continue to lose moisture ONLY if it is stored & transported properly.
I'd say that 19% is too wet to paint. If properly stored, air is permitted to circulate around it and continue the drying process. This all depends on how it was stacked and stored from the time it left the kiln until you purchased it. If kept indoors, it should've continued to lose moisture. If left outside, to the elements, then it's possible that the moisture content could increase above the specifications of the kiln-dried process. This would render the "kiln- dried" marking as useless. The best way to determine if wood is properly dried is by using a moisture meter. Period!
If you don't have one and plan to do a lot of this type of work, then I'd suggest you get one. Or if you know someone close by who does, and will allow you to borrow it, then do so. Sorry, if this aint the answer you want to hear.
Good luck! (Might make a good Christmas gift though, eh?)
-------------------- Bill Cosharek Bill Cosharek Signs N.Huntingdon,Pa
bcosharek@juno.com Posts: 703 | From: N.Huntingdon, Pa, USA | Registered: Dec 1999
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