Does semi-gloss poly become less glossy with each application?

I am in the process of laying down multiple thin wipe on coats of poly to a project.

The first half dozen coats were done in gloss. Then I switched to semi-gloss for the final two coats. The first coat of semi-gloss, still left the wood with a pretty high sheen.

Will the semi-gloss (i.e. less sheen than gloss) nature continue to build with additional coats of semi-gloss additional or will I need to go to satin if I want the surface to be less shiny?

i.e. is the non-gloss sheen just determined by the top coat or does it build across multiple coats?

Reply to
blueman
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You did stir well? The matting compound sinks to the bottom and the top layer is therefore high gloss. I'm not saying that is what happened but not uncommon.

r
Reply to
Robatoy

If you are happy with the finish but not the gloss, try knocking it down with a fiber matted scouring pad (kitchenware or cleaning aisle). On large surfaces, use one under an orbital sander. A coat of wax keeps it looking good.

P
Reply to
cselby

Yes, the sheen is determined by the top coat (assuming it is applied heavily enough to actually make a decent film thickness); i.e., varnish does not melt into preceding coats as do lacquer and shellac. Since the semi-gloss has a matting agent in it it must be thoroughly stirred before application else you are putting on more glossy.

Reply to
dadiOH

Probably more common than it should be.

If that is not the case, and you DID mix well, consider this:

The flattening materials in your finish are finely ground particulates held suspended in solution by the viscosity of the material. (When well stirred!)

But look at your material and its application. The reason you have to put 10 coats of finish on your piece is because the thickness of the material left behind is quite thin. You apply the material, and wipe a great deal of it off. This means you are wiping off the flattening agents as well as the resin finish.

So when you apply a top coat of a product with a different reflective factor, you will probably have to apply several coats to acheive "semi gloss" as you final gloss. And since you are going over a previously finished area, you are probably not putting on as much finish as you think. If you are putting the new finish down on a smooth, previously finished project and then wiping smooth, you may have less than a mil of finish actually on the surface.

That will probably dry to less than 1/2, probably more like 1/3 of a mil of finish. Check out the manufacturer's recommended final finish thickness; I would almost bet without seeing the stuff it will be 3 mil.

Of course, all of the above depends on your "hand" and application technique, but if I were you I would keep putting on the finish to get to the desired gloss/reflectivity.

Personally, I know there is a large camp of folks that like to use the gloss, then knock it back with 4X steel wool or a scoth brite pad, but getting every single crack, crevice, corner, and detail finished to exactly the same reflectivity perfectly across the whole project can take a huge amount of time.

Just keep on going, you'll get there.

Next time, you might want to start with a piece of scrap from your project and try the semi gloss on all coats compared to your present method of half semi and half full gloss. Depending on the actual finish, there probably won't be that much difference in the final appearance.

Robert

Reply to
nailshooter41

"Most" varnishes do not meld in to the previous coats. Gel varnishes do in fact meld into preceding coats. With gel varnishes you do not have to scuff the precious coat before applying the next and you can repair a previous coat that may have a glob that you missed while wiping by simply applying more of the gel varnish to that area. That glob will soften and smooth out.

A few other oddities about gel varnishes, there is no stirring to mix in the matting agent, it stays permanently suspended. Additionally I have yet to see a gel varnish that comes in a "gloss". Because gel varnishes go on thin and yield a finish that gives spraying a run for its money in smoothness, it seems like a gloss finish would be a naturally "easy to apply finish" with a gel. I'll have to e-mail Lawrence McFadden and find out the skinny on that. ;~)

Reply to
Leon

Check the link below. At the bottom of the referenced page (if the link works), you will see another link to a pdf labeled "Bartley Gel Finishes brochure". When you click on the link and open the pdf, you will see an old standard, Bartley wipe on varnish < in satin >. While I have used their satin, I have actually never used their gloss.

As a sidebar, while it may be different now, in the ancient old days of gel finishes, they did want you to gently stir (not mix) the product before use to make sure the product was "consistent in application". Maybe long truck rides in hot trucks that distributed to warehouses were a consideration at one time. Dunno.

But, the OP was asking about poly. Is your new favorite a poly or a varnish? Don't confuse me, as I was telling someone this last weekend (that can't afford for me to finish his piece of furniture) that you had come across a finish that you liked a lot, and had great luck in application.

If it is a varnish, he will probably try it. If it is a poly, he won't. It looks like LMF makes the wipe on poly, and Bartley's makes the wipe on varnish.

Going to the LMF site does no good. When their home page opens it ONLY describes a polyurethane finish as their wipe on gel.

BUT... when you go to the bottom of that page and load their pdf on Bartley gel, the can they show in the brochure is clearly marked as varnish.

So is the LMF poly the product you are using or are you using the Bartley's varnish?

Details, please.

If LMF doesn't have a gloss wipe on, don't worry. You can get gloss wipe on from Minwax (hey don't laugh - it's pretty good!), Cabot, Valspar, Old Masters, Zar, and a few others.

I have used the Old Masters (excellent) and the Minwax (almost as good) personally, but not the others in gloss wipe on.

Let me know which finish you are using that you like so much, por favor.

Robert

Reply to
nailshooter41

Yes I stirred and stirred and stirred...

Reply to
blueman

That's interesting, I didn't know that. So one could French polish with it? I may have to break down and try some :)

Reply to
dadiOH

Blueman:

In reading through some of the responses to your inquiry it becomes clear that some of the responders are not.

The silica flatting agent is in suspension, not in solution. There is no such thing as being suspended in a solution.

Do a bit of reading on how the gloss is knocked down by the silica breaking up the light and how finish hardness and the use of flatting agents are related. This will help you make a decision about what to use for a top coat.

The fact that something contains polyurethane does not preclude it from being a varnish. These are definitional issues but not being mindful of them can lead to confusion.

The Lawrence - McFaddden and the Bartley gel finishes both contain polyurethane.

Jeff Jewitt's Homestead Finishes site is a good place to start looking for answers.

Regards,

Tom

Thos.J.Watson - Cabinetmaker tjwatson1ATcomcastDOTnet

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Reply to
Tom Watson

I never saw the link but did see the pdf Bartley brochure. I didn't see the gloss there either. The web site was moving dead slow and I did not look further.

Yeah actually thinking back, I witness a liquid that will form on the top if it sets for several weeks/months, I'll stir that in. But for daily use stirring was/is not necessary.

Yeah I was mostly commenting that you could meld with the gel products.

Is your new favorite a poly or a

LOL, let me start off with my definition of a varnish.

A paint containing a solvent and an oxidizing or evaporating binder, used to coat a surface with a hard, glossy, transparent film. The smooth coating or gloss resulting from the application of this paint.

I consider any clear finish that adds a top protective layer, a varnish.

Personally I started using Bartley gel "Varnishes" in 1989 and only last year switched over to the LMF after learning that LMF had acquired the Bartley line of finishes. I cannot tell any difference between the resulting clear finish of the Bartley's or the LMF. That said, I switched only because of the free offer from LMF and stayed with the LMF over the Bartley varnish because of a more consistent application. Often I got Bartley varnishes that were inconsistent in viscosity in the can.

That is what it looks like however again I cannot tell the difference and again I consider polyurethane a varnish as per the definition above. Neither have the plasticy look after 3 or 4 coats.

I see the same but did not see the Bartley's gloss varnish

Currently using LMF, "was" using Bartley's for about 19 years. Now that LMF manufactures the Bartley's products there may be a more consistent quality in their product.

I don't see a difference in the two except that the Bartely's seems to add a bit of a golden tone to the wood, LMF seems to leve the color more natural.

I'm basically lazy in this respect, I want only to use one product. I prefer satin to any other finish, however some of my customers prefer gloss. When I need a gloss finish I use General Finishes Arm-r-Seal gloss. I wipe on the first sealer coat, wipe off the excess and let dry. I follow that with a scuff sanding, and a single coat applied with a quality/Wooster "foam"brush. It goes on heavy with that final coat and you have to apply it and not work it. Again that finish looks sprayed.

Again I use the above mentioned General finishes for a gloss finish but find that the glossy finish shows wipe marks if the final coat is not applied with a foam brush. The foam brush holds tons of varnish.

In the last 8-9 months it is the LMF Gel Poly , and again I cannot see a viable difference between it and the Bartley' except for the warmer golden tone of the Bartley's. Both require thinner/oil based product for clean up. Oh, one thing I do notice, the LMF gel has a purple'ish tint in the can, the Bartley's looks more like Vaseline.

Leon

Reply to
Leon

Also read Tom Watson's comment. He has the same thoughts on a "Varnish". He also mentions that Bartely's and LMF both contain Poly.

Something to think about and or investigate further.

Reply to
Leon

Well, the "evaporating" qualifies shellac as a varnish. That's pushing a bit. And a "paint" usually contains pigment and is not a "transparent" film.

But that's just me feeling pedantic this morning :-).

In reference to the subject of this thread, yes, multiple coats of a finish with a flattening agent will decrease the gloss with each additional coat. Assuming of course that it's been stirred :-). The problem is that multiple coats also make the wood appear cloudy. I tell customers if thy must use such finishes, use gloss for all but the last coat, which they can do by NOT stirring. Or just use gloss and rub it out.

Reply to
Larry Blanchard

LOL, Varnish is a resulting finish not necessarily a type of finish. Carburetors can develop a varnish inside.

Reply to
Leon

Did you sand the gloss first before applying your next coat. Poly does not adhere well to itself so each coat should be sanded before the next

Reply to
Lou deGonzague

Yea, verily, you got me there :-).

I've had recent experience with gasoline based varnish on a motorcycle that'd been sitting for several years.

Reply to
Larry Blanchard

You have my deepest sympathies. 4 cylinder, probably 4 carb problems. Been there done that.

Reply to
Leon

Some varnishes have polyurethane resins. Some do not. It is my understanding that most resins used in varnish are cheap polyester resins. They are soft, flexible, and do the trick for most of us.

Polyurethane resins are added to make the finish coat harder than without, and more abrasion resistant.

But almost all (wanna be careful here...) polyurethane finishes have the same basic characteristics and formulas of varnishes, but with polyurethane resins, less the polyesters. In the end, the poly products should be harder due to their resins.

My concern for the difference in the two would be the color they impart. Any varnish product I have seen imparts an amber hue, and as they age it seems to really come on strong. Some of the polys go on almost clear with little ambering, but don't always warm up some types of wood.

As far as LMF and Bartley's go, I would suspicion from further reading that formulas may actually be significantly different between their respective varnish and poly products. Your experience would seem to bear this out when you describe the purplish tint of the LMF (we used to call that "chroming") vs. the plain look of the Bartley's when both are in their respective cans.

But... who knows for sure. Probably only LMF.

So many manufacturers now are simply revamping their old formulas it is hard to know if you are getting the newest technology in coatings or just an old lady in a new dress.

Robert

Reply to
nailshooter41

It certainly is a lot to keep up with. Anyway, the LMF on Maple changes the color little, more like a water based finish.

Reply to
Leon

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