I have been purchasing 1/2" SimpsonŽ brand MDO, factory primed on one side. The un-primed side is factory stamped as 'Simpson Backer'. Now I have a customer that needs a two sided 1/2" MDO sign and the local supplier no longer stocks two sided material.
I have several sheets of the primed one side material in my inventory, and he guy insists on wood, not AlumaLite.
This 'Simpson Backer' looks similar to the old unprimed material, and my supplier claims that it is 'not required' to paint it.
My question is, has anyone successfully primed and painted this 'Simpson Backer' side, or are there some paint adhesion issues with the backing?
Posted by Bob Rochon (Member # 30) on :
The thing that worries me is Simpson doesn't make MDO anymore, they sold thier plywood division a little while back, and I have never seen a preprimed MDO board with only one side primed. Posted by William Bass (Member # 4929) on :
Since the plywood is pre-primed, I'm assuming that you are purchasing it from a sign supply store (could be wrong, I guess).
Have you tried a lumber supply company. While the sign supply stores here, where I'm located, sell pre-primed MDO, I prefer to buy it un-primed from the lumber company.
The MDO I get has the paper laminate on BOTH sides. I never heard of the Simpson Backer or whatever. YOU MUST SEAL THE EDGES VERY WELL.
The technique I've always used for sealing edges (and there are several ways--but I've only ever used one) is to fill all edge gaps with good quality, exterior, quick dry putty (the putty should NOT be water-based: water-based putties usually require a 24hr cure time), then prime twice and paint once...or twice (if both sides will be finish-coated).
Since I have to prime BOTH sides of MDO, this works out right. I prime the edges when I prime the face. I prime the edges when I prime the back. I paint the edges when I finish-coat the face. (gotta sand lightly with an orbital sander or sanding block after priming). Edges sealed in this fashion usually hold up well (in my experience). Can't say how that would work if the back is UNPAINTED because it has some kind of unique backer on it, though. I've never seen or heard of Simpson backer!
Posted by William Bass (Member # 4929) on :
Also,
Back when my dad ran a sign shop, we usually used two sheets for "double-faced" signs. My dad didn't like to paint both sides of the same sheet for some reason.
So IF it is true that Simpson backer doesn't require painting (I'm leery of that claim, tho) and you can't get real MDO somewhere...then consider using two sheets.
In such a case the two sheets are separated by the posts they are nailed/screwed to, as I recall. I don't mean that the two sheets are butted up against each other back-to-back (as I could see that possibly leading to water-damage issues.)
I would still prefer MDO from a lumber company, I think (just because I am unfamiliar with the Simpson backing--I hate being unfamiliar with stuff).
Posted by Randy Campbell (Member # 2675) on :
I get one or two sided crezon 1/2" or 3/4".
Posted by Brad Ferguson (Member # 33) on :
Curt, The Simpson backer has a waxy feel. Have you ever felt HDO, the concrete form stuff. It kind of reminds me of that. I don't think paint will stick to it well. Also, compared to the front, the back side is never finished as well before they put the backer paper on. I've seen knot holes that leave a void under the paper.
It would be interesting to call Simpson with the question.
Brad in Kansas City
Posted by Leonard Sappington (Member # 4562) on :
I can buy 2 sided 1/2 MDO unprimed at Menards... I also get 2 sided Primed from N.Glantz and Sons delivered to my door... Glants is a little more expensive, but it is nice to have it delivered...
Edge sealing is a simple precedure.. I simply sand the edges, give it a slight roll, and then use tightbond II brushed on in 2 coats. I learned that trick from a post from John Deaton I believe... Thanks John
[ March 25, 2005, 06:39 AM: Message edited by: Leonard Sappington ]
Posted by Jeff Ogden (Member # 3184) on :
The Simpson "backer board" is left unprimed on one side, so that you can glue it to the back of a HDU sign. That's why it's called a backer board. If it was primed on the glue side, your glue would be stuck to a coat of paint, not the board itself.
And yes, you can paint it, and yes, it usually is slightly rougher looking than the front, but once the sign is lettered most of that will dissappear to the eye. You should always sand mdo before priming. And if it was me, I would re-prime that factory crap on the front, after sanding it. I use an exterior oil-base white primer, tinted toward the topcoat. I too use the TitebondII glue on the edges after filling the voids.
Hope this adds to your signmaking fun... Posted by Amy Brown (Member # 1963) on :
Ditto what Jeff said except I use waterbased primer. I have painted the backsides after scuffing and never seen a problem.
Posted by Curt Stenz (Member # 82) on :
Jeff and others, thank you for your responses. I will for sure scuff, clean and oil prime the Backer.
Not to change the thread, but as for sealing edges, I always round the edges slightly, sand, and prime edges with oil primer thinned with about 30-40% linseed oil. After this dries (usually 2 days) I second coat with straight oil primer, two coats enamel on the face, and I have some jobs still looking good for up to 8 years now.
If only I could keep the enamel from chalking.
Posted by Si Allen (Member # 420) on :
The first thing that you must know....there are many grades of MDO (crezon)! Not all grades are suitable for exterior signs.
Simpson was bought out by Olympic Panel Co.....and they now produce MDO:
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