06-23-2023, 09:38 AM (This post was last modified: 06-23-2023, 03:41 PM by Bencuri.)
I have a problem with painting enamel on wood. When I apply the first coat, it flares nicely, but when I apply the second, it does not. I do wait 24 hours between the coats as the manufacturer suggests. But yet when I apply the second coat, the brushmarks remain after drying. This problem appears almost every time I use enamel paints, regardless of brands. When I apply them to porous surface, they flare, but when I apply them to metal or a first layer, so something that is not porous, the brushmarks remain. Can you suggest something to improve this? Maybe spraying something between coats?
I am using matte version of the paricular brand here. The chemical content is alkyd resin, the solvent is mineral spirits. I have the same problem when using varnishes here, where the solvent is mineral spirits. This problem does not occur, when I use water based version of enamel paint. That one flares, no brushmarks, no bubbles. But those are not very thick. Solvent based enamels leave a thicker film, it is less time to apply the finish if you use those.
What you call "flare" is what we call "flow out", if I understand you correctly. The link you provided is for SW's waterborne All Surface Enamel, which is an acrylic. It's not an alkyd nor is the thinner mineral spirits, so I'm not sure what product you are using. I've used that paint, and it works pretty well, but not as well as SW's Emerald Urethane Trim Enamel. It is a hybrid emulsion paint that still uses water as the thinner, and it flows out very well. Benjamin Moore makes a product called Advance, which is a hybrid with an alkyd resin that flows out very well, too. It just takes a very long time to dry and forever to cure, but it's a great, durable product once it does.
With any waterborne paint you can extend the time it has to flow out by adding a product called Extender. It's sold here by Benjamin Moore and also by General Finishes. 3 to 6% by volume often will double the time a paint has to flow out. Thinning it up to 10% with water will increase the time as well. You can combine the two approaches, too. I used SW's ProClassic, another waterborne 100% acrylic, to do the side of a built-in cabinet to which I was retrofitting new doors that had been sprayed. To get the smoothest possible finish, I thinned it 10% with water and added about 5% Extender AND I used fine nap roller to apply it. It looks like it was sprayed.
(06-23-2023, 12:57 PM)jteneyck Wrote: What you call "flare" is what we call "flow out", if I understand you correctly. The link you provided is for SW's waterborne All Surface Enamel, which is an acrylic. It's not an alkyd nor is the thinner mineral spirits, so I'm not sure what product you are using. I've used that paint, and it works pretty well, but not as well as SW's Emerald Urethane Trim Enamel. It is a hybrid emulsion paint that still uses water as the thinner, and it flows out very well. Benjamin Moore makes a product called Advance, which is a hybrid with an alkyd resin that flows out very well, too. It just takes a very long time to dry and forever to cure, but it's a great, durable product once it does.
With any waterborne paint you can extend the time it has to flow out by adding a product called Extender. It's sold here by Benjamin Moore and also by General Finishes. 3 to 6% by volume often will double the time a paint has to flow out. Thinning it up to 10% with water will increase the time as well. You can combine the two approaches, too. I used SW's ProClassic, another waterborne 100% acrylic, to do the side of a built-in cabinet to which I was retrofitting new doors that had been sprayed. To get the smoothest possible finish, I thinned it 10% with water and added about 5% Extender AND I used fine nap roller to apply it. It looks like it was sprayed.
John
LOL, indeed, it is flow out
The link is my mistake though. This problem I am describing is present with solvent based enamel here, I wanted to link something similar to that. I just did not pay attention to that on the link it is water based. I don't have problem with the water based. At least not in most cases. The photo of the waterbased that I uploaded is a little bit misleading, there is a coat of solvent based under it, the ridges come from that, the water based totally flows out and takes the shape of the surface under it. If I use only water based those small ridges are not there, but even on the surface visible on the photo it is much better than using solvent based only. You can see that if you compare the second and third photo.
So for solvent based enamel, are there also some product with that you can improve the flow out? And avoid bubbling? That is also a crucial problem, some bubbles are always there all the time. You can also see that on the photo, lots of bubbles dried into the paint. If you can recommend something maybe I would order that from eBay because here I cannot really find anything.
Quote:So for solvent based enamel, are there also some product with that you can improve the flow out?
yes, in the U.S. it's called Penetrol.
Perhaps your paint is too thick also, and need thinning a bit. And 24 hours is 24 hours, not let it dry overnight. You might be surprised how many people gloss over the difference......including professional painters
Why are you so secretive about where you live and what products you're using ?
Are you an A.I. machine ?
Even if you're in Russia or China with a language comprised of a non arabic alphabet - we have access to translator programs. And some of us have lived/worked /painted in countries outside the USA.
Your pics suggest to me that your paint is skinning over (drying) too quickly. They also suggest you aren't sanding , vacuuming, and tacking between coats. 320grit or 400g between coats will help you get a smother finish too.
What would an AI benefit from if it knew how to apply enamel properly?
I live in Hungary.
You are correct. I did not send between coats. One reason is because when I used simiar products in the past and sanded, it made no sense, the brushmarks were there. On the other hand, you see on the first photo that the paint flew out perfetly on the bare wood. That wood was not sanded either, just smoothplaned. And it happens like that all the time. On the wood these enamels flow out, after the first coat they do not. On metal they don't flow out anyhow. Seems to me as if on non porous surface the bursh marks do not vanish.
And the other problem, how can you eliminate the bubbles? They are always there, even on the first photo I uploaded, you cannot see on the photo, but hear and there they do appear.
We don't have Penetrol here but this guy here suggests I can use lamp oil for the same purpose. What do you think? That one I can get here: https://youtu.be/9YzhxVUNtuk?t=80
There's really only 2 reasons to sand the preceding cots, One would be to smooth out the finish, usually eliminating dust nibs, the second would be to provide some tooth for the subsequent coat. I don't think either one is your problem. Typically when I run into this it's because the finish is too thick and needs to be thinned (oil based) or you need the extender product (water based). Bubbles can also be a result of your brushing technique, you might read something about "tipping off" with your brush, which is lightly moving the tip over the surface. Generally I'll do this with varnish, but I've not had to do it with paint.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
(06-24-2023, 04:52 AM)fredhargis Wrote: There's really only 2 reasons to sand the preceding cots, One would be to smooth out the finish, usually eliminating dust nibs, the second would be to provide some tooth for the subsequent coat. I don't think either one is your problem. Typically when I run into this it's because the finish is too thick and needs to be thinned (oil based) or you need the extender product (water based). Bubbles can also be a result of your brushing technique, you might read something about "tipping off" with your brush, which is lightly moving the tip over the surface. Generally I'll do this with varnish, but I've not had to do it with paint.
I see the point in sanding for smooth surface. The problem is that still do not eliminate the brush marks. I tested it this week. I will try thinning on the second coat.
06-24-2023, 08:15 AM (This post was last modified: 06-24-2023, 08:18 AM by tomsteve.)
blowing the pictures up and mentioning bubbles, you have solvent pop- solvents that need to offgass/evaporate from the first coat were trapped by the 2nd coat and didnt have a chance to evaporate. in other words, even though you waited 24 hours, the first coat wasnt ready for a 2nd coat. to help the first coat offgas,dry quicker, some air circulation can help.
im not sure how oil based paints are where you live but here i find them to be rather thick out of the can. i like to thin them down a bit for both brushing and spraying. otherwise i find the mill thickness to be way too much causing problems.
What wood are you using? Tom's picture showing solvent pop makes no sense to me with an oil based paint, only one with a volatile solvent. So your paint either is not a traditional oil based paint like here in the US, or your wood is outgassing.
As far as sanding goes, yes, absolutely, even on your freshly planed wood. Sanding creates a uniform structure for even absorption of the paint. And, yes, again, between coats, especially if you have brush marks. Applying another coat over a surface that isn't dead flat is just going to result in a thicker layer with those same brush marks, plus whatever new ones you added. You have to have a flat surface for every coat.
What kind of brush are you using? You need a high quality brush and good technique to get a smooth surface.
06-24-2023, 04:06 PM (This post was last modified: 06-24-2023, 04:08 PM by Cabinet Monkey.)
(06-23-2023, 09:52 PM)Bencuri Wrote: What would an AI benefit from if it knew how to apply enamel properly?
I live in Hungary.
You are correct. I did not send between coats. One reason is because when I used simiar products in the past and sanded, it made no sense, the brushmarks were there. On the other hand, you see on the first photo that the paint flew out perfetly on the bare wood. That wood was not sanded either, just smoothplaned. And it happens like that all the time. On the wood these enamels flow out, after the first coat they do not. On metal they don't flow out anyhow. Seems to me as if on non porous surface the bursh marks do not vanish.
We don't have Penetrol here but this guy here suggests I can use lamp oil for the same purpose. What do you think? That one I can get here: https://youtu.be/9YzhxVUNtuk?t=80
(06-24-2023, 06:19 AM)Bencuri Wrote: I see the point in sanding for smooth surface. The problem is that still do not eliminate the brush marks. I tested it this week. I will try thinning on the second coat.
You have several issues you are dealing with at the same time. Fixing only one will not get you where you want to be.
1. You really should sand - even fresh planed wood. I can see a surface that isn't glass smooth in your first picture. It's smooth, but not glass smooth. Won't solve your problem by itself though.
2. Your paint is too thick and is drying too fast. You must thin it with an appropriate solvent for your paint. Since you won't tell us what it is, can't help you with specifics.
3.Lamp oil will likely work just fine, but you still might need to thin the paint with a solvent. And a bigger problem for you is "what is lamp oil" in Hungary ? Kerosene ? Liquid parafin ? Olive oil ? And what did mr. youtoob use for lamp oil and in what kind/type and brand of paint ???? The exact components might make the difference -or- they might not. Raw linseed oil will work in most enamels too.
The whole purpose of all these "additives" is to make the paint dry at a slower pace - so that the brush marks have time to flatten out before they skin over. Remember -this stuff also extends the number of hours before you can re-coat your project !
This is the stuff we're talking about for use with WATER BASED PAINTS. I'll be you a plate of your mother's gulyas that this company has an additive for OIL Based Enamels.
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