Can I wipe-on regular Urethane?

[radhak]

Of course, I already did, so the question is post-facto !

Finishing red-oak with Minwax's Spar Urethane (Helmsman), this morning I did not to brush it (hate the brush marks), but thinned it a bit, 15-20% with mineral spirits and wiped on with cloth.

I avoided brush marks, but after the first coat, I get a feeling it's gonna take a 4 or 5 coats - the first was very thin! But it also felt less sticky, so maybe I don't need to wait all the 4-6 hours they said?

And I did not use any special technique - just went over with the cloth covering all area.

Anybody thinks I'm making a mistake here?

[cgallery]

I've been experimenting applying wipe-ons (which is essentially what you've made) with foam brushes.

The problem I've always had w/ wipe-on poly is the same you're experiencing, which is slow to build requiring lots of coats.

The foam brush seems to be providing a decent compromise: A little thicker coating of a thinner finish, with no brush marks.

But I will also warn that my current project is not the smoothest substrate. So I still have to experiment w/ finely polished woods.

[BigguyZ]

You can use regular poly as a wipe-on, but I'd say you definitely want to cut the finish with some mineral spirits. That'll allow it to flow and self-level better.

[cabinetman]

Your procedure sounds OK, but I'll make a suggestion on the finish selection. Spar's do not harden up like an interior oil base varnish or oil base polyurethane. They are not intended for interior use. They remain somewhat flexible. They are intended for outdoor use to cope with that environment.
.

[radhak]

Your procedure sounds OK, but I'll make a suggestion on the finish selection. Spar's do not harden up like an interior oil base varnish or oil base polyurethane. They are not intended for interior use. They remain somewhat flexible. They are intended for outdoor use to cope with that environment.
.

Uh oh. It does say 'interior / exterior' on it.

If I want to change to poly, can I keep going, or do I need to strip the first coat first?

[cabinetman]

Uh oh. It does say 'interior / exterior' on it.

If I want to change to poly, can I keep going, or do I need to strip the first coat first?

If it was my project I would strip off the spar. Finishing over it would keep it from curing. Did you give up on waterbased polyurethane?

BTW...what's the project?
.

[cgallery]

Your procedure sounds OK, but I'll make a suggestion on the finish selection. Spar's do not harden up like an interior oil base varnish or oil base polyurethane. They are not intended for interior use. They remain somewhat flexible. They are intended for outdoor use to cope with that environment.
.

See that is the difference between a pro's answer and mine.

I didn't catch the "Spar."

And it wouldn't have mattered, I didn't know what it meant.

[herb fellows]

As far as wiping on poly full strength, I've found it to not do so well, kinda spotty for whatever reason.
If you thin it 50/50, it will go on better, but you really do need lots of coats for real protection, probably 5-6 is realistic if it has anything to do with moisture (ie: a table top).
While I find the first 3 coats or so to not look so good, by the time you get to 5-6 it improves a lot.

[radhak]

Yeah - full strength poly is too thick for my liking; never liked to even brush it that way. Have diluted it only 20% though; maybe should dilute a bit more.

The project is the trough-style book rack I had a thread about couple of months ago.

[SARGE..g-47]

Most definitely Ditto Cabinetman on not using Spar for furniture. I brushed on a coat of Spar on my mailbox post 4 years ago and it has not cured yet as it is not made to fully cure. It has to be flexible for outside exposed to weather. Luckily my FIL at the time warned me about using it for inside back in the mid 70's.

As far as wiping poly... it is my standard procedure and I would not go back to a brush as it is so simple and eliminates runs and bubbles altogether. But.. I don't cut it fully to 50-50. I mix in one of those clear plastic jars you get in the grocery that has mark lines. It's almost fool-proof!

My first intial coat is 66 1/3%- 33 1/3% with a one to two ratio using naptha which evaporates quicker than mineral spirits. Let it dry the full 4 hours so it can harden. Lightly ( I do mean lightly) go over it with Abra-lon 1000 which is about the same as 600 wet dry. You are only taking tiny nibs as wiping produces only tiny ones. Vacuum the dust and ready for coat two.

Second coat of same.. repeat the procedure. The third coat is then cut to 50-50 as the first two filled pores and smoother over. On a table top I will apply two coats of 66-33 and two of 50-50. On parts that will not see abuse I only use the two 66-33 and one of 50-50.

I personally think letting poly build too deep is a mistake and one I used to make. By doing so the finish will look en-cased in plastic and if you didn't let those early coats fully cure before proceeding they probably never will down underneath. The first two coats fills pores.. the third and final gives the finish look. I rub out with 0000 Liberon steel wool adn wax after final coats after waiting a week for the poly to fully gas off and harden. My kitchen nook table.. coffee table get heavy use and they are wiped daily with a wrung out sponge. Both tops followed the above schedule.

BTW.. when wiping make a long pass with the grain. The poly is thin enough it will not drag as pure with a brush and fully cover your swath so you should not have to go back over it at any point. That is a big mistake with a brush and many make it leaving high and low spots. The wiping is about as close to the holy grail using poly as you can get IMO. I used to hate to finish but not it is a breeze.

If you want to see the results I have a carcass curing now. Be glad to get a picture on request as I will probably post the project early next week.

[radhak]

Thanks sarge, for that detailed response! Helps a lot! And that photo would sure be good, though you did paint a nice picture with your text!

[pelligrini]

Great info Sarge, thanks for sharing.

[SARGE..g-47]

Thanks sarge, for that detailed response! Helps a lot! And that photo would sure be good, though you did paint a nice picture with your text!

Here ya go Rad... I am simply going to post a couple of pictures from two projects I completed within the last 6 months. I have the current crochet-lamp table in clamps at the moment even though the finish has been applied. Still had to add and glue the inner frame between the top strechers which the tissue box tray is attached too. Long story on tissue box trays.

One is a fish tank table for our Beta.. it has the four coats mentioned as some water drops occasionally get splashed adding water or feeding. The other is a printer-shredder table that has a printer on top and shredder on bottom. This top has only three coats. Computer desk-hutch with 4 coat top as it sees a lot of traffic daily.

So.. you can judge for yourself as both these see activity daily and one is exposed to water. BTW... I use Min-wax Satin and then break that sheen down a hair with a rub-out with Renaissance Wax which get applied with 0000 Liberon steel wool. Kills two birds with one stone using the 0000 to apply the was... simply be sure to allows apply with the grain and not rotary as you can car wax when applying.

Back to the shop to build a small letter holder rack for her table (work-bench in essensce) while glue is drying.... She keeps me busy which is probably not a bad thing considering my bad repution for gettin' in trouble.

[cgallery]

One of these days I'm doing to be able to build/finish projects like Sarge.

I've said it before but I've always liked the finishes on your projects.

[SARGE..g-47]

You're quite welcome Erik... and thanks Pelligrini. Trust me that until about 10 years ago I used to totally butcher finishes. One day I said enough is enough and got some help with advice locally. Probably the wisest thing I ever did turning night-mares into not a problems.