sanding between coats

[Scott Dunsworth]

I have been using 220 paper inbetween coats of varnish. I am using easypoxy hi build varnish from pettit. My question is it allright to use scotch brite pads for this inbetween sanding? I have two coats on the boat and many more to go, and it seems these pads( medium) would be ok. My spars are Douglas fir and the have high places that the 220 seams to clean off. It looks like the pads would follow the wood closer. BUT as I have learn in building this boat everything does not work well just because it sounds good. Some advice please!

[Allen Foote]

Yes, you can use the scotch brites. The idea here, is to create something for the following coat to cling onto. The scotch brite will scratch the surface enough to rough it for the next finish coat. I preffer to sand with 220/350 between 2 coat. I wouldn't use the scotch brite until there is enough varnish laid to fair it with 350 grit, then use the scotch brite between finish coats. Think of them as the plastic equivalance to fine bronze wool. When the surface isn't glossy and its white/opaque...stop sanding. I use the scotch brites to remove the amine blush from epoxy coats...they will stand up to varnish.

[lumberdude]

I'm not exactly an expert, but I will relay what my experience has been over the past few months and 10 coats of varnish.

I've tried the scotch pads, and I like them when my previous coats turn out well. (very few bubbles, no dust etc.) But when the coat didn't go as well as desired, I find that the sandpaper, and I use 400 grit, tends to smooth out the blemishes where the scotch pads will only scuff the surface. Keep in mind you aren't trying to remove much varnish from the previous coat, only to scuff the surface for a good bond with the next coat.

The down side of sanding is more dust, which you have to carefully remove before going on to the next coat.

Good luck!!

lumberdude

[Bob Cleek]

400 grit sandpaper on varnish! Wow! What are you building? Pianos? LOL I'd add that you should build up your coats without much concern as to finish (well, within reason) until you have eight or ten down. Then you can sand it really fair. 120 or 220 is fine. Good varnish properly applied should cover the rough kicked up by 220 for sure. The biggest problem lots of people have with varnishing is that they sand every coat off after they've put it on!

[lumberdude]

Which is exactly why I use 400 grit! So I will leave the last coat in tact. But I'll admit, I think I'm the only one that uses it...

lumber

[Scott Dunsworth]

Thanks for the help. Using the scotch pads should speed things up for me. When I get down to the last coat two coats I will wet sand with sand paper and hopefully be able to lay those last coats on smooth and beautiful. PS. My wife is about to have a cow I dont even have this boat in the water yet, and study plans for another came last week. Whats a fellow that loves to smell wood and varnish suppost to do?

[doorstop]

On cabinet work I use 0000 steel wool, would this be acceptable on boat bright work?

[nedL]

It's not a good idea to use steel wool on a boat (Especially a Salt Water boat). For years to come you will find little rust stains appearing in places you never even imagined & never had the steel wool close to.

[doorstop]

I did wonder about that which is why I posed the question, thank you.... when "The Vessel" gets going it shall not be sullied with 'Steelo'.

[Dan Cavins]

Hi Scott. God knows I am not the expert but here is my experience: after clogging sand paper and uneven sanding and scratching on my kayak I got mad and scrapped that plan. What the hey, I went at it with the 3M sanding pad. Like a little sponge it is soft and self contained, rides the curves, doesn't dig in or take off the coat you last put on. And you can shake it out and wash it out (let it dry!), no clogging. In short, it
worked great.
Now I refinished last year and because I'm a knucklehead I tried a new plan. I like to keep myself busy you know. Back to the 3M sanding sponge. Is it right? I don't know, just worked for me. See ya', Dan.