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FESTOOL DISCUSSIONS => Festool How To... => Topic started by: 10digit on June 02, 2008, 10:30 PM

Title: Suggestions for polishing waterbased finish
Post by: 10digit on June 02, 2008, 10:30 PM
I am putting the finishing touches on an entertainment center I built to house a 50" plasma TV and would like some suggestions on how to get the poly smooth without too much effort.  I say this because there are a total of 4 parts to the unit - a center console, 2 towers and a center arch.  This is a whole lot of area to tackle with lots of nooks, crannies, raised paned doors, drawers and shelves - you get the idea.  The unit is made out of quarter sawn white oak solids and veneer plywood.  I stained the unit with an oil stain, waited several days and then sprayed water based Minwax Polycrylic with an HVLP conversion gun (my first time ever using a sprayer).  The finish came out very good without runs, or orange peel.  However the finish does not have that smooth feel we all strive for.  I have a Rotex sander and would like some guidance on how to use it to smooth and bring up the sheen to a nice semi gloss luster.  The plywood is rather open pored - I'm not looking for glass smooth otherwise I would have had to fill the pores before finishing.  Again I just want a nice surface to touch without an overly complicated process considering the amount of surface area to work.  Is the Rotex the right machine or is this a manual process?
Title: Re: Suggestions for polishing waterbased finish
Post by: Michael Kellough on June 02, 2008, 11:12 PM
RW gave you a ton of info so I'll just suggest you make sure you have enough finish on there to work with. You sure don't want to cut through it.

The best features of WB finishes is how soon you can apply another coat and especially how soon you can sand smooth  the build coats.
Title: Re: Suggestions for polishing waterbased finish
Post by: Scott W. on June 02, 2008, 11:12 PM
Good solid advice.

Thanks RW

Scott W.
Title: Re: Suggestions for polishing waterbased finish
Post by: woodshopdemos on June 03, 2008, 08:38 AM
I will add one thing to RW's excellent advise...let the WB finish fully cure. It might feel hard to the touch but you have to worry about the layers underneath. Start buffing out uncured finish can be a real mess and one impossible to fix. I let finish stand for 5 days as the "cure time". and that represents days in a nice warm environment (i.e. room temperature.)

In the future, you might want to sand very lightly with 320 paper between coats....not all coats but maybe after number 1...or use a sanding sealer and sand that. that can be WB as well.
Title: Re: Suggestions for polishing waterbased finish
Post by: 10digit on June 03, 2008, 09:08 AM
I did sand with 400 grit between each coat of WB finish.  The finish is level with only very minor dust nibs here and there.  I am definitely not looking for a high gloss, mirror finish.  Because the grain is open, this will never happen, nor do I want it to.  What I struggle with is sanding 600, 800, 1000 and 2000 and having a finish that looks cloudy or smeary (is that a word?)  I have finished numerous projects using cherry and other woods and have noticed the same problem.  After the final coat of finish, (using oil based product) I try to finish the finish - that is I flatten the sheen with 600 grit and then go progressively higher on the grits using a lubricant and finally a paste wax.  The result is never consistent in sheen.

I am hoping that the Rotex's polishing capabilities would result in a more consistent sheen and a little quicker result.
Title: Re: Suggestions for polishing waterbased finish
Post by: Michael Kellough on June 03, 2008, 09:15 AM
I will add one thing to RW's excellent advise...let the WB finish fully cure. It might feel hard to the touch but you have to worry about the layers underneath. Start buffing out uncured finish can be a real mess and one impossible to fix. I let finish stand for 5 days as the "cure time". and that represents days in a nice warm environment (i.e. room temperature.)

In the future, you might want to sand very lightly with 320 paper between coats....not all coats but maybe after number 1...or use a sanding sealer and sand that. that can be WB as well.

It's funny that WB finishes dry enough to sand between coats in 1 hour (in most cases) but they need around 100 hours to dry cure enough to polish.
Title: Re: Suggestions for polishing waterbased finish
Post by: woodshopdemos on June 04, 2008, 06:54 AM
I will add one thing to RW's excellent advise...let the WB finish fully cure. It might feel hard to the touch but you have to worry about the layers underneath. Start buffing out uncured finish can be a real mess and one impossible to fix. I let finish stand for 5 days as the "cure time". and that represents days in a nice warm environment (i.e. room temperature.)

In the future, you might want to sand very lightly with 320 paper between coats....not all coats but maybe after number 1...or use a sanding sealer and sand that. that can be WB as well.

It's funny that WB finishes dry enough to sand between coats in 1 hour (in most cases) but they need around 100 hours to dry cure enough to polish.

I agree. The difference might be heat. When you sand between coats, you are lightly sanding the surface and no heat. When you start to buff out, there is a lot of heat.
Title: Re: Suggestions for polishing waterbased finish
Post by: Michael Kellough on June 04, 2008, 10:19 AM
I will add one thing to RW's excellent advise...let the WB finish fully cure. It might feel hard to the touch but you have to worry about the layers underneath. Start buffing out uncured finish can be a real mess and one impossible to fix. I let finish stand for 5 days as the "cure time". and that represents days in a nice warm environment (i.e. room temperature.)

In the future, you might want to sand very lightly with 320 paper between coats....not all coats but maybe after number 1...or use a sanding sealer and sand that. that can be WB as well.

It's funny that WB finishes dry enough to sand between coats in 1 hour (in most cases) but they need around 100 hours to dry cure enough to polish.

I agree. The difference might be heat. When you sand between coats, you are lightly sanding the surface and no heat. When you start to buff out, there is a lot of heat.

That makes a lot of sense John.