Primer for OSB type composite trim - Smartside

[LG63]

I’m planning to replace some cedar trim with Smartside composite boards. For those that aren’t familiar it’s basically an OSB type product molded with a cedar grain pattern and available in 1x2’s up thru 1 x12’s. It reminds me enough of OSB that I’m still not fully convinced it’s good for the long haul but after comparing other options I’ve decided to give it a shot.

There will be a several boards that I’ll need to rip to a narrower width thus leaving a cut edge. Obviously it’s preferred to leave factory edges uncut but the manufacturer does state that cut edges can be sealed an acrylic latex primer.

So I’m looking for the best possible primer I can find since a few of the boards will be horizontal runs where water drops are certain to form on the bottom edge every time it rains.

Left to my own devices I’d probably go with a Kilz or Zinsser product. For the painting experts out there, is there a primer available that is particularly well suited for this application?

 

[BillK]

I thought it was factory primed ??

 

[readhead]

Read again. He is ripping the material. I've used a lot of this material and have used a good quality acrylic primer on cuts.

 

[gsloan]

Zinsser Bulls Eye 123 would be my first choice. I have been using it for interior and exterior for quite a few years now with no disappointments.

 

[bedn0009]

Oil based primer on all field cuts.

 

[Norcal]

Oil based primer on all field cuts.

Oil based products are not as flexible as latex & wood / wood "products" do move, a good latex primer will be much better. There is nothing more expensive then cheap paint

 

[K'ledgeBldr]

I get what you're wanting; but...


That sure sounds like a lot of extra work for a "maybe" fix. Why not just use PVC in the sizes you need and never have to replace it again? And there is some that has a woodgrain texture.

 

[LG63]

I get what you're wanting; but...


That sure sounds like a lot of extra work for a "maybe" fix. Why not just use PVC in the sizes you need and never have to replace it again? And there is some that has a woodgrain texture.

I looked at PVC but couldn't justify the cost difference. Also Smartside comes in 16 foot lengths which will help avoid joints in several places.

As for the amount of work, I'll only be priming a few edges so not a lot of effort there.

 

[alwaysFlOoReD]

Can you put an angle on your cut to keep water at the outer edge?

 

[LG63]

Can you put an angle on your cut to keep water at the outer edge?

I'll give that some thought. My hunch is that the angle wouldn't make much difference because of the way water tends to capillary/wick uphill anyway. Certainly couldn't hurt.

I first came across Smartside over a year ago when my neighbor was using it on his garage. I decided to do my own non-scientific experiment and took a few of his scraps and nailed them to the inside of my privacy fence. Fast forward 15 months and I haven't noted any swelling even on the cut, non-primed edges. So I think it's actually fairly forgiving but I still want to do everything I can to avoid problems.

 

[TheOtherChris]

I first used smart side trim on my house nearly 3 years ago. Like you, I had to rip a few pieces and I used KILZ oil based primer followed by latex color. I had pieces on the ground by the garage all winter that showed no signs of swelling on the bare cut ends the following spring.

I just used the same product on the addition to my current house and again used KILZ oil based primer on the cuts prior to latex paint.

Very happy with the product.