Bob Hollinshead;24700 said:
If it were my piano and I wanted to make positively sure of the best results I'd let the epoxy cure up well before blocking, and apply a sealer coat before paint. Will that poly coating that's on it absorb solvent and become unstable, swell? A few coats of cured and blocked epoxy sure would put my mind at ease knowing solvent wouldn't reach it.
No, that factory poly coating is extremely durable. My friend has worked at the piano shop for 30 years. He says NOTHING the ever tried would eat into the piano poly. They tried Acetone, lacquer thinner, MEK etc over the years while working on pianos. I've sprayed SPI epoxy over the piano poly before with good results. I'm confident the SPI won't eat the poly.
moving on...
I sprayed on two coats of SPI yesterday on the P400 grit prepared piano
It has been over 12 hours now at 65 - 70 degrees. I haven't touched it yet but it looks dry. The only "issue" I have is what looks like exaggerated fish eye on a top edge of the piano. I'll post a picture later if I can. I used SPI water borne W&G remover. Perhaps I didn't rub it all off the rim or let it flash long enough before priming. It is easy to sand that area down and re-apply epoxy as I'll be spraying a few more coats of epoxy on the piano as I sand it down before paint.
Let's talk about a seal coat please. Why would I do that - in this case. What I mean is, I'll be blocking this thing smooth. If I spray on a sealer, I would be blocking
that smooth as well because the just sprayed seal coat won't be as smooth as my blocked surface. Since I'm blocking before paint, what difference is there if I paint over blocked epoxy or blocked thinned epoxy? When I sand, I won't be sanding through the epoxy, just blocking the orange peel and dust out of it.
I can understand sealing a car where body filler or metal is exposed after sanding. There isn't any painted metal on this piano.
Do I really need to spray on a thinned seal coat of epoxy? As mentioned. I would block that before paint anyways.
Thanks.
Please keep the info flowing. I enjoy learning all I can.
Danford1
EDIT: Here is a link to the project pictures. I will be updating this a couple time a week.
http://www.flickr.com/photos/14256847@N08/sets/72157631686472491/