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Why does my finish always dry rougher?

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Forum topic by DTrak posted 01-03-2016 03:20 AM 753 views 0 times favorited 16 replies Add to Favorites Watch
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DTrak

39 posts in 562 days


01-03-2016 03:20 AM

newbie question.. I am using an oil+urethane finish on a tabletop. I sand it down real smooth, put on a coat, and then it dries with little bumps. I can buff them out with 0000 steel wool and apply another coat but the same thing happens when it dries, and I know on the final coat, I can’t buff. Is it dust in the air that sticks in it as it dries, and if so, what can I do about that? It’s not like I can dry it in a vacuum.


16 replies so far

View conifur's profile

conifur

955 posts in 616 days


#1 posted 01-03-2016 03:30 AM

What are you using to apply the finish?

-- Knowledge and experience equals Wisdom, Michael Frankowski

View pintodeluxe's profile

pintodeluxe

4858 posts in 2278 days


#2 posted 01-03-2016 03:54 AM

Shaking the can instead of stirring will cause this.
Foam brushes will cause this.
Dust settling in the wet finish can cause this (solution to all problems is using a quicker drying finish like spraying lacquer).

By the way you can wet sand the finish with a 1500 grit sanding sponge and a spray bottle of water.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View a1Jim's profile

a1Jim

115202 posts in 3042 days


#3 posted 01-03-2016 04:06 AM

If you poly is water base poly the last thing you want to use is steel wool.

-- http://artisticwoodstudio.com Custom furniture

View clin's profile

clin

514 posts in 461 days


#4 posted 01-03-2016 04:11 AM



If you poly is water base poly the last thing you want to use is steel wool.

- a1Jim

Why is that?

-- Clin

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a1Jim

115202 posts in 3042 days


#5 posted 01-03-2016 04:15 AM

Because you will get bumps and rust all over your project from all the little pieces of steel wool left in the grain. water and steel =rust if you want to use something to smooth down under a water base poly use synthetic steel wool or sandpaper.

-- http://artisticwoodstudio.com Custom furniture

View clin's profile

clin

514 posts in 461 days


#6 posted 01-03-2016 04:19 AM



Because you will get bumps and rust all over your project from all the little pieces of steel wool left in the grain. water and steel =rust if you want to use something to smooth down under a water base poly use synthetic steel wool or sandpaper.

- a1Jim

I think I may have used some steel wool with some water base poly on some small thing or another in the past. I don’t recall an issue, but will keep this in mind for any future, more significant project.

-- Clin

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a1Jim

115202 posts in 3042 days


#7 posted 01-03-2016 04:22 AM

View bondogaposis's profile

bondogaposis

4032 posts in 1816 days


#8 posted 01-03-2016 04:27 AM

Is it dust in the air that sticks in it as it dries,

Probably, you can make a dust lid out of a piece of 1/4” ply and run some screws into to to make legs then set it on top of the table right after you are done applying finish. If possible try to do your finishing some where besides your dusty shop. If not, wait to apply finish on a day that you won’t otherwise be working in your shop creating dust. Lightly hand sand between coats w/ 400 git sandpaper, wipe it down w/ MS dampened rag. Use a brown paper sack to rub out the final coat, then wax.

-- Bondo Gaposis

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MadMark

978 posts in 918 days


#9 posted 01-03-2016 05:23 AM

The poly crystalizes a little as it dries. Lightly buff with 2000 grit wet/dry automotive sand paper. Follow with paste wax & buff to a lusterous shine. Thin the poly 50%-50% and try a dry brush on the last coat.

A cotton buff with light polishing compound can give a mirror finish. Read Maloof’s book.

M

-- Madmark - Madmark2150@yahoo.com Wiretreefarm.com

View mudflap4869's profile

mudflap4869

1156 posts in 924 days


#10 posted 01-03-2016 07:09 AM

My first thought was, did you use a tack cloth to remove ALL the fine dust off the project before you put the finish on. Spray adhesive lightly on a soft cloth, it does a great job and it is wash-and-reusable.

-- Still trying to master kindling making

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DTrak

39 posts in 562 days


#11 posted 01-03-2016 01:08 PM

Thanks for all the feedback.
I am using arm-r-seal oil+urethane satin. Is that water based? It doesnt say.

I am using cotton rags to apply.

I am reticent to introduce wax because that means I will need to re-wax periodically and I already know I love the way this looks and am afraid to mess with it.

The synthetic steel wool is a good idea although the 0000 version of that brand did not get great reviews. I imagine 400grit sandpaper wood shed too, right? Maybe less than steel wool.

The dust lid idea makes sense although this is a very large dining table so it would not be a small job to create.

I was very careful to remove all the dust before applying the next coat, but the table is in a very open layout house and over the 12-24hrs that I wait to apply coats, dust prob comes from somewhere. Unfort I cant close off the room.

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DTrak

39 posts in 562 days


#12 posted 01-03-2016 01:14 PM

Maybe I should use this on my random orbit sander instead of steel wool?
http://www.amazon.com/MIRKA-GOLD-HOLE-DUSTLESS-SANDPAPER/dp/B000XY0VZM/ref=sr_1_3?

View WoodNSawdust's profile

WoodNSawdust

1417 posts in 641 days


#13 posted 01-03-2016 01:45 PM



I am using arm-r-seal oil+urethane satin. Is that water based? It doesnt say.

I am using cotton rags to apply.

- DTrak


My can of Arm-R-Seal is defiantly oil based.

Make sure that any rag you are using will not shed lint.

If the problem is bubbles in the finish you can try thinning the finish with mineral spirits. This will keep the finish wet longer giving time for the bubbles to bust and allow the finish to flow eliminating any marks caused when applying.

-- "I love it when a plan comes together" John "Hannibal" Smith

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BurlyBob

3688 posts in 1730 days


#14 posted 01-03-2016 06:01 PM

Cotton rags will leave lint. Try Polyester cloth. I will fold the cloth so I have a 3-4 inch wedge sort of thing. I wrap it in a piece of nylon panty hose, dip in the poly and use it like a squeege. By playing the light and thinning the poly you can get a very nice even coverage. I’ll let it dry really hard and give it a light going over with 600 wet/Dry. The results are a mirror smooth finish. Trust me on red oak that can be a serious challenge.

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DTrak

39 posts in 562 days


#15 posted 01-04-2016 03:38 PM

burlybob, great tip, I will try that! thanks

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