Hi, Could I ask some advice regarding the above. I have lined my garage with plywood sheets (which have quite a nice smooth sanded finish) after insulating the inner walls and ceiling, and now going to paint them white to make it lighter. Would I need to prime them first, or could I get away with just undercoating them then emulsioning them white, or just leaving the undercoat after a few coats if it came out O.K.? Ive seen a local store that has Dulux Trade Undercoat at £20 for 2 x 5 litres, which I think is a good deal, and just wondering if this would do, especially with it being just a garage, however I don't want to ruin the finish as Ive spent a few bob on it. If just the undercoat was O.K. to use would I need to thin it at all or just roller it on as it is? Any ideas? Thanks
I would use a 2 coats of quick drying waterbased primer/undercoat (Glidden or Dulux for high opacity) rubbed down between coats and then finish off with 2 coats of quick drying acrylic eggshell applied with a mohair roller for a good finish.
good choice Astramax. Philph, which ever method you use make sure that you do not mix an oil based with a water based, its not a good combination either way round. they dry at different speeds and cracking can be the result.
Mick that is not a problem as either oil/solvent or water based would be fully dried before being overpainted. I use quick drying primer undercoat on wooden garage door frames when I paint blocks of compound garages and then Dulux gloss them any time between 2 an 4 hours after applying the QD undercoat, never had a problem with that. Time is money, more so now with the 2010 VOC extended drying times.
ive seen the results of mixing oil and water based myself Astramax, ive seen the cracking. best avoided and no chance taken in my book. but as always, each to their own.
The paint pigments are basically the same the difference is the mobile phase being either oil/solvent or water, as you say each to their own but I like to move with the times testing and challenging new products. I've never seen or experienced cracking using this method. Are you suggesting you would not or never have painted over Zinsser Bullseye 123 with an oi/ based paint?
if its the newer blue tin then i have used it as a primer yes, but i would have then used water based undercoat and top coat. personally i use the bin primer for most bare wood, that knots and primes in one. but im not going to experiment with customers paint jobs incase it fails because most of my customers are regular and i have painted a number of properties several times over. so i stick to what i know works.but i do accept that we each have our own methods.
Masonry paint is my get-out-of-everything paint. So far I've used my pot of matt black paint on rough-sawn exterior timber constructions, an aluminium-framed exterior light, my iron stair banisters and a textured repair to my geetar amp. And, on my smooth timber fascias. I've used white-with-a-dab-of-black-to-give-grey on a small shiplap shed at school where nothing else would adhere (due to the weird stuff the previous cove had applied). Oh, and I've also used it on masonry and stone work. In every case, it's stuck like a sticky thing, and the finish has been hmmmmm. I reckon it'll stick to ply just niftily. Perhaps an issue might be bleeding from resin or other stuff in the ply which could show up on a light colour.
DA, i would definitely not risk using masonary paint on masonary or brick, its going to react for sure.
Philph, equally you could use cuprinol jasmin white wood stain, i use this a lot and it long lasting in harsh conditions. i wouldnt recommend using it on fresh tanalised wood because the tanaliser leaches through, also it would be best to knot the ply first (if there are any knots)
The o/p could use a number of different products such as Sadolin Superdec or Barn Paint all would do the job and provide an acceptable finish as would previously mentioned products.
i hear what you are saying John, but i would still use caution,things dont always do what they say on the tin.
(I thought JJ was tacking the mick out of Mick for his spells.) Anyways, OP, this is what to do; Paint yer ply with masonry paint. Big, fat roller. Job done. Knots won't be a prob, 'cos ply basically don't have none. Well, not deep ones anyhow; they'll be a ply-layer thick at t'most. And I doubt they'll be resinous. Guess what I'd do in the OP's situation? Yep, use masonry paint. And the only reason I'd use masonry paint rather than straight-forward emulsion (which would also work...) is that the masonry would be more durable. OP, guess what you should do? Yep, masonry paint - straight on. Or else silk emulsion. You know it makes sense...