problems leveling a varnish finish

[Eric Husta]

Hello All,

I have been reading this forum for some time but have just recently joined the forum so I apologize for asking for help rather than offering it as a first post. Truth be told, I'm not much of a wood worker and apparently even less of a finisher. I am in the process of refinishing a solid cherry table top and just finished applying two coats of Arm-r-seal semi gloss.

The table looked great and I decided to level the finish before proceeding. I realized after applying the 3rd coat that I didn't level enough to produce a uniformly dull finish and I also saw what I'm guessing were 'friction streaks' under this new layer. I then took a leaf from the table and leveled it with 320, 600, then 0000 steel wool. The surface looked good but when I applied a new coat and it dried, it was bad. It was clear as a bell but you could see every single stroke of scratching.

So I have a few questions I'm hoping someone can help me with. First, how do I remove these scratches and maintain good adhesion between layers? I feel like I would need to buff this surface to a super fine surface in order to not see these scratches. I understood a urethane finish would be tricky but what choice do you have if you need to level the surface? What should I do now, mechanically force my way through a few layers and wet sand the surface until I see no scratches before proceeding to rebuild? Strip it all off and use something else?

I have read many of the threads on this forum but I'm still unsure how to proceed. It's really frustrating because the top was really beginning to look great and now I'm not sure I can get it back. Any help would be greatly appreciated.

Thanks,

Eric

[Steve Friedman]

This is one of the best Arm-R-Seal discussions ever:

http://www.sawmillcreek.org/showthre...Seal-questions

I am a novice, but have used Arm-R-Seal without problems since I kind of got the hang of it. The key things (for me) were discovering blue Scotts shop towels, remembering not to try to "work it," and to use a light touch. Here's what I do after sanding:

1. Sand to 220 and clean well with tack cloth.

2. Apply Arm-R-Seal with a blue paper shop towel. Wipe it on, but don't work it. Howard Acheson described the process this way:

". . . Apply a wet coat with an applicator and merely get it on. Think of a 16 year old kid working as a busboy at Denny's you have sent over to wipe off a table. Sort of rub/swirl the the material on like you would if you were applying a paste wax. Don't attempt any straight strokes. The applicator should be wet but not soaked . . . If you have missed a spot, ignore it - you will get it on the next coat."

3. Before the Arm-R-Seal starts to dry, I take a clean piece of blue shop towel and lightly wet it with some varnish. Then, using a VERY VERY light touch, I remove any excess varnish and let it dry for at least 24 hours

4. Scuff sand to 320 or 400

5. Repeat steps 2 & 3. Wait another 24 hours.

7. Scuff sand to 400

6. Repeat step 2 & 3, but then don't touch the varnish for at least 2 weeks (4 is better). Then, knock down any nibs. Some folks advocate using a brown paper bag, but I tend to use a 4,000 grit pad and it works fine.

Also, best if used in reasonable (like at least 60 degree) temperature. Also, I'm pretty sure that Arm-R-Seal needs lots of fresh air flow to cure. I tried to get it to cure in my basement (because it was too cold outside) and it took forever.

Hopefully others with more expertise (and from whom I learned) will chime in. I think it's a very easy product to use. You just need some time to play with it until you get the feel.

Steve

[Eric Husta]

Hi Steve,

I have read that thread several times and plan on trying to build the surface as I move forward. It did help me pinpoint my problem. Let's assume I am at this stage,

"Ignoring any of these will leave marks that are tough to get out. Getting these marks out requires some aggressive sanding to flatten out the surface and starting over."

How do you flatten the surface without leaving sanding marks? Even the 0000 steel wool left fine scratches that showed right through. Will wiping on the finish in several thin coats fill these in and make them invisible? I thought that is what would happen but even with a weak light the underlying, sanded surface looks horrible. Do these scratches disappear as you wipe on additional coats? Should I just level the whole thing with 220 and start again?

Thanks for the reply.

Eric

[Prashun Patel]

Yes, the first or second wiped coat after aggressive flattening can be cloudy or scratchy. As long as the scratches are truly from your abrasives in the 320+ range, yes, more of coats will eventually hide the scratches. But the varnish needs to build to level those scratches. Wiping and rubbing out are finnicky bedfellows. Leveling tends to work better with brushed on varnish. Then you can be a little more aggressive without risking burning through. A wiped on finish burns through quickly - in which case you'll get what looks like peeling where you sanded through the ultra thin wiped on coats. These too will eventually disappear under subsequent coats of varnish.

If you are intent on leveling, then you might consider brushing on a few coats, and letting them cure nice and hard before you begin with the abrasives.

Alternatively, you can do what i do. keep wiping on in coats of 3, sanding with progressively finer abrasives, gently, not worrying too much about the scratch pattern, but just trying to get a smooth surface - without burning through. With each subsequent round, the finish gradually improves.

The three keys to wiping succesfully are 1) wipe on very thin coats, 2) move quickly and with a light touch and don't come to 'tip off' or remove swirls, 3) be patient and prepared to do many coats.
A lot of people lack the discipline and patience to know that the quality improves with each coat, and they end up violating 1 and 2.

[Eric Husta]

Thank you for the information. This definitely helps as I was scared to death to continue to bury scratches that I may have to end up fixing by removing the material I am applying. I did foam brush the first two coats and it looked really good. I just figured I should level the surface before continuing and that is where the trouble started. I let it cure for several days but I must not have completely leveled because I could see the difference in the spots where the finished had been cut and those where it hadn't been touched. Now I see definite scratch patterns under the new layer of varnish even after leveling.

The only strange thing is that not only does the surface feel ultra smooth but the scratches do appear to be "encapsulated" within the finish. I will add an additional coat this evening and see if it lessens the effect. The only bright side in all this is at least I am experimenting on a table leaf and not a half...

[Steve Friedman]

Cool. This is an all-New Jersey thread. Prashun knows more than I will ever, but I'm a bit confused. If you sand to 220, with the final sanding by hand, make sure there are no sanding marks left, and clean off all the dust before applying any finish, you shouldn't ever be sanding back to bare wood. Therefore, all you are scuff sanding is the prior coat of varnish. Although it may not be necessary, I always wait till the coat dries so I can scuff sand (usually to 400 grit) before applying the next coat. That way, any scratch marks left by the scuff sanding should not be any deeper than the last coat and I shouldn't have to go through two layers of varnish to fix something.

The keys (I think) are taking the time to get the surface properly prepared before you apply any varnish, using a light tough when wiping off any excess varnish (is that called tipping off?), and being careful to clean the surface after each scuff sanding. Arm-R-Seal will level itself, but I don't think it's going to level out anything more than a single layer of varnish.

I don't like 0000 steel wool with Arm-R-Seal. I have used the foam brushes, but the blue shop towels really are the best. That and using a really good quality 400 grit sandpaper with a very light touch. There's not a lot of varnish left on the surface after each coat, so it's really easy to sand through it.

Hope that helps.

Steve

[Eric Husta]

Yes, sorry I may have confused the issue by asking too many questions. I was asking about two different subjects at once. I laid on two initial coats with a foam brush and was actually quite impressed at how it was looking. I then leveled with a block and didn't get a uniform and even surface as evidenced by the streaking in the next coat when it dried. Once this happened I guess I panicked a bit and really put some effort into leveling out one of the table extensions. The surface was completely flat but scratched up pretty good. I kept going up in grit all the way to steel wool because the scratches just wouldn't disappear.

When I coated this surface and it dried I was shocked at easy it was to see the scratch pattern. This is where the real dilemma was for me. I wasn't sure if I could keep building over this to get rid of the scratches or they needed to be removed. I just put a coat on this evening and will take a better look tomorrow. I have a big light at a shallow angle to help me but you didn't even need to see the patterns.

The second question really was about application technique as I was thinking if I build a bit slower wiping rather than brushing maybe I would be able to control the scratch pattern a bit more? I don't know. I'm such a rookie at this stuff it's not even funny but I can tell you this... I am too much of a perfectionist to sit at this table every night and see those scratches...not going to happen. I will strip it again if I have to in order to get it right.

Thank you both for your input. Every bit of someone else's knowledge will help.

Eric

[Prashun Patel]

I am curious as to why the scratches seem encased. That happens when you dont sand to a high enough grit. Can you. Post a picture? And what kind of varnish is it?

one more thing. I am not a pro like steve, howie, or scott. But i have made a lot of mistakes and have gradually learned how to do it better but not perfectly.

[Eric Husta]

I'm curious too but I put another coat on tonight and will see how it looks in the morning. If it persists I will attempt to take a picture. It may be hard to see though. I am using ordinary Arm-r-seal semi-gloss. I thought the same thing about the grit and that's why I went to the steel wool. It's obvious at this point that i did something wrong with the sequence of steps. Hopefully I can bring the table leaf back but I am really hoping to avoid having to put all this effort into the main table.

Eric

[John TenEyck]

My experience after having used gallons of Arm-R-Seal is that once you screw up it's better to strip it off and start fresh rather than thinking you can save it if you just do this or that. Just a waste of time and product. I've never been able to apply it uniformly with a foam brush but I have seen beautiful examples from others who have. I use a shop paper towel, like many others, with great results. I wipe on a wet coat and do not go back over it, and I never wipe any off - it's not an oil finish and it sets up too fast to do that w/o creating streaks. I let the first coat dry completely - often 24 hours. I scuff sand between coats with a 320 mesh thin foam sanding pad, just enough to knock off any nibs. You aren't trying to level it, and it doesn't need it because wiped on coats are so thin it doesn't create high/low spots. 3 or 4 coats usually look great, and I don't think I've ever applied more than 6 coats. The chances of creating problems increases the more coats you apply after you have a continuous film.

John

[Eric Husta]

So I checked the new coat this morning and the scratches are definitely receding. It still has a touch of "streakiness" in the finish for lack of a better term. Looking at a reflection of the morning grey sky through the windows really shows the flaws. My next question is should I continue to use a foam brush because this is what I started with or switch to wiped on thinner coats as I proceed to finish? It sounds as though you guys prefer to wipe it on.

Can you mix both techniques and if so would it hurt to change now? Will wiping on the final coats provide any benefit over the foam brush?

Eric

[Eric Husta]

Thanks for the info John. That is what I was afraid of hearing but I kind of suspected it with the leveling. The ultra-thin coats of wiping may have negated the need to aggressively level. I feel kind of like I opened Pandora's box once I hit it with the block to level and I have been having trouble getting back to a nice finish. My arms already hurt from the thought of removing all this material. Do you have experience starting over? If I strip it would I have to sand off all the stain as well?

Eric

[Prashun Patel]

It won't hurt to mix techniques. It's an accepted technique to build using brushes, level, then wipe on the final few coats.
Are you stirring your arm-r-seal? Not stirring can cause streaks.

[Eric Husta]

Yes, stirring very well but I will admit the cloudy streaks do give the appearance of uneven occluders.

[John TenEyck]

Thanks for the info John. That is what I was afraid of hearing but I kind of suspected it with the leveling. The ultra-thin coats of wiping may have negated the need to aggressively level. I feel kind of like I opened Pandora's box once I hit it with the block to level and I have been having trouble getting back to a nice finish. My arms already hurt from the thought of removing all this material. Do you have experience starting over? If I strip it would I have to sand off all the stain as well?

Eric

Yes, I had to strip a table top that I hosed up trying to brush on the Arm-R-Seal. The top was dyed first with Transtint. I used KleanStrip Premium stripper and it took off the Arm-R-Seal about as fast as I could brush it on, and it took out most/all of the dye, too. If you used a pigmented stain I'm pretty sure it would take that off too. I did not sand again after I stripped, there was no need to. I just made sure I neutralized the top real well with Naptha after I got the stripper off, let that dry, then started over.

Don't give up. Arm-R-Seal is beautiful when you get it right. The streaks you are getting are not due the flatters in the product. There aren't many in the semi-gloss sheen, and they stay in suspension for hours before settling. Streaks are the result of not getting it on uniformly. The goal is to flow it on as smoothly as possible, with enough liquid so that it can self level. If you apply too little, you will definitely get streaks. If you apply enough to flow out, but then go back over it you will get streaks. Flow it on from one end to the other, leave it be, and move on to the next "row". You should be able to do a 3' x 5' table top, for example, in 4 - 5 minutes. If you can't apply it fast enough with a paper towel, use a micro fiber cloth formed into a ball with a smooth exterior. It will hold more without dripping and let you lay down a smooth coating. In either case, it really helps to pour out the Arm-R-Seal into a container large enough that you can dip into without it slowing you down - the can is too small.

John



John