What's the purpose of sanding between coats? Is it to make the coating
surface rough so the second coat would adhere better or is it to sand
off imperfection such as bubbles?

On Thu, 12 Mar 2020 20:00:10 +0630, Jerry Salinsky
wrote:

What's the purpose of sanding between coats? Is it to make the coating
surface rough so the second coat would adhere better or is it to sand
off imperfection such as bubbles?


Both.

https://www.minwax.com/wood-products...-spar-urethane

" .. to ensure an even finish
and proper adhesion of additional coats. "

" Note: For exterior surfaces or for previously unfinished wood,
three coats are recommended. "

John T.

On 12/03/2020 20:16, wrote:
On Thu, 12 Mar 2020 20:00:10 +0630, Jerry Salinsky
wrote:

What's the purpose of sanding between coats? Is it to make the coating
surface rough so the second coat would adhere better or is it to sand
off imperfection such as bubbles?


Both.

https://www.minwax.com/wood-products...-spar-urethane

" .. to ensure an even finish
and proper adhesion of additional coats. "

" Note: For exterior surfaces or for previously unfinished wood,
three coats are recommended. "

John T.

Thanks for quick reply.

I wonder why it mentions "for previously unfinished wood." When
refinishing, don't people sand off, completely, previous coating and
leave bare wood? How does that differ from "previously unfinished wood"?

On 3/12/2020 8:30 AM, Jerry Salinsky wrote:
What's the purpose of sanding between coats? Is it to make the coating
surface rough so the second coat would adhere better or is it to sand
off imperfection such as bubbles?

Â* Yes .

--
Snag
Yes , I'm old
and crochety - and armed .
Get outta my woods !

On 3/12/2020 8:53 AM, Jerry Salinsky wrote:
....

I wonder why it mentions "for previously unfinished wood." When
refinishing, don't people sand off, completely, previous coating and
leave bare wood? How does that differ from "previously unfinished wood"?

A. Not always, no.
B. Even if do, if ring porous wood like oak will still be some left in
pores. Even if not porous, sanding finished wood rarely leaves anything
close to as pristine a surface as new wood. Removing a whole surface
layer past the oxidized outer skin like planing a drawer front, say,
would be essentially new wood surface.

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