I have used Behlen Rockhard Varnish on a table top. My first time with this product, which I will probably never use again. I started a new thread, but you can see my troubles from another recent thread. I thought this question different enough to warrant a new thread.
I have a sufficient thickness of varnish on the top, via a combination of 7 coats wiped on (thinned 50/50), and 2 coats full strength. My brushing skills are apparently poor, because I had to sand out about a thousand air bubbles. After I did that, my fear forced me to wipe on 2 more thinned coats and abandon brushing.
My problem is that the surface does not have a uniform sheen. I am convinced that the dull areas have quite a thickness of varnish. It isn’t like the dull areas are down to bare wood or anything like that.
My question is, since I want a satin finish, can I wait a couple weeks and rub out the finish? Will the dull and shiny areas rub out to a uniform sheen?
Alternatively, can I apply another (satin) clear finish material on top of the table right now, like a poly product which I’ve never had a problem with?
I am concerned that I have ruined a months-long project by trying Rockhard. The problem may have been made worse by virtue of the fact that the table top is large (48 by 78 inches) and maybe I need to finish it in sections??? At least for the tipping off technique with the brush.
Thx for all advice and responses
Replies
What kind of brush did you use? "A thousand bubbles" suggest either a poor-quality brush, or bubbles already in the varnish (perhaps from too-vigorous mixing).
-Steve
Steve,
It was a Wooster $20 China Bristle brush, 3 inches wide.
There were no discernible bubbles in the mix before I brushed it on, so I'm guessing it was "just" bad technique. The first coat went on much better than the second actually. Maybe the problem was how I cleaned the brush between coate? Mineral spirits, then soap and water. Wrapped in brown paper between coats. But there were no nits of dried varnish in the second coat, which I would have expected had I done a poor job of cleaning the brush between coats.
Dan
Well, I can sympathize, but I'm afraid I don't have any real answers for you. My (limited) experience tells me that lots of bubbles mean "something's wrong," but it can be hard to figure out exactly what that something is.
It's like when the leaves on your houseplant start turning brown along the edges, and you look it up in a book, and the book tells you that the plant is either getting too much water or not enough water, or too much fertilizer or not enough fertilizer, or too much sun or not enough sun....
-Steve
Steve,
Thx, but I'm beyond worrying about what caused the bubbles. When I am in a more serene mood I will reflect on that. Right now, I'm trying to salvage my finish. Do you have opinions as to my underlined questions?
Thx for responding,
Dan
When you say that the sheen is not uniform, do you mean the sheen of the as-brushed finish? That is, you haven't rubbed it out at all? If so, I think the answer to your first question is yes.
The answer to your second question should also be yes, but I'd wait a few days to ensure that the existing varnish is good and hard.
-Steve
You can certainly sand the existing finish to both flatten it and remove the sheen. However, wait until the finish is fully cured. I'd wait at least four weeks. Use first, some 400 paper on a sanding block and sand with the grain. Then sand with 600 grit. Use a mixture of mineral oil and mineral spirits as a lubricant. Wipe the surface frequently to see where you are.
After the above, let everything fully dry and see how it looks. You may be done. Or, Wipe on a couple of coats of finish. I don't understand why you just didn't keep using the wiping technique. Brushing a large panel is something that takes lots of practice and skill.
After sanding, you can also apply a coat of paste wax using 4/0 steel wool or grey scotchbrite. Apply by rubbing with the grain and then buff.
Howie and Steve,
Thx for your responses.
Steve - to answer your clarifying question: yes, the dull and shiny surface is without any attempted rubbing out.
Howie - you asked a good question. The reason I tried brushing is because I was getting the "some areas glossy, some areas flat" effect when I was wiping on a diluted mix. I thought it was due to the fact that I was wiping on such a thin coat, that maybe I was essentially wiping it all off in the areas that then appeared flat. I thought the thicker, brushed coat would give me more margin for error in this regard.
Given the fact that I don't want to wait 4 weeks to complete the finish job and give the table to my friend, do you agree with Steve that I can now apply a poly satin product safely and call it a day??? And, can the finish material be Minwax Wipe-on Poly or one of the water-based finishes that I've used successfully in the past?
Regards,
Dan
"Given the fact that I don't want to wait 4 weeks to complete the finish job and give the table to my friend, do you agree with Steve that I can now apply a poly satin product safely and call it a day???"
Well, I said to wait, too. Howie just wants you to wait longer. I guess my approach would be to wait as long as I could stand to wait. If you can make a mark with your fingernail, even a little one, you need to wait.
Any polyurethane should work over cured and scuff-sanded Rockhard, but you do run a risk if it's not fully cured.
-Steve
Steve and Howie,
Thx for your advise. The finish passes the fingernail test right now.
Just for kicks, attached is a photo of the top which I am trying to finish. I think the dye/glaze combo did a nice job of making the figure pop in this curly maple. (Lou Irion of Irion ans Sons was kind enough to pick out the wood for this project himself, if you recognize that name. Lou now runs a hardwood lumbering and milling operation in the PA northwest, but Irion and Sons was known nationally as a period reproduction shop. They made a number of Goddard Townsend "Newport" style repros for my home.)
Regards,
Dan
You can lightly scuff sand with 320 paper now but it you want to sand out some of the brushmarks, you need to let the finish cure throughout its full film thickness. While it can feel tackfree to the touch, the secondary and most important step of curing takes 3-4 weeks. Second, mixing finishes can be risky. Behlen uses some rather agressive thinner/solvents in it's finish. While they all should evaporate rather quickly, attempting to use another finish too soon can be risky.Howie.........
I have tried to read carefully and still don't see the answer--what sheen of varnish are you using? I assume satin, since that is the finish you wish to attain. I think the answer is that you have not stirred your varnish adequately throughout your finishing process which must be done. Otherwise the "dulling agents" are not uniformly in suspension and you will get glossy areas and dull areas. (If someone else said this already, my apologies).
Don't go to the brushing technique. Wipe on is so foolproof--if you keep your diluted varnished well swirled before applying.Gretchen
Gretchen,
Thx for your response. Rockhard Varnish only comes in gloss. I want a satin finish, but had intended to achieve this by using the gloss to get the thickness and protection I need, then either 1) use a final coat of another product in satin, or 2) abrade or rub out the gloss product to get the satin sheen I wanted. Why didn't I just use mulitpe coats of a satin finish product to start with? Because I had read in numerous places that the flattening agents. especially with multiple coats, would obscure the grain. This is perfectly logical, right? So rather than have many layers with diffracting particles, many sources recommended using gloss (with no diffracting particles), then topping off with one layer with these particles.
Maybe you have the solution as to why I was getting flat and gloss areas when I was wiping on a reduced varnish blend (and this is why I tried brushing). I was not actively stirring the blended mixture (50/50 with Behlen Reducer), so maybe some times I was swiping on thinned varnish, and other swipes were mostly with Reducer? That sounds logical, and would explain my results with wiping. Unlike shellac, which obviously needs to be stirred when you mix a 1 pound cut, the varnish/reducer blend doesn't obviously need to be stirred, visually.
Dan
Didn't know that about Rockhard. Yes, maybe your mixed varnish wasn't really mixed. Can't really know. But I have done many things using satin varnish thinned and not had the problem so many report.
The way those who do not advocate building the finish with satin have suggested is to build with the gloss and then put the final coats of wipe on satin.Gretchen
Rock Hard is not an easy product to use. I threaten to use something else, but I always come back to it, because nothing I've used looks as good or protects as well.
I once dented a top that was only days away from being shipped, and there was obviously no time to recoat with the varnish. Out of desperation I turned to padding lacquer. The results were excellent. I was able to get a consistent sheen; one that could be rubbed out to a satin if that is what I wanted. Of course the padding lacquer is not as durable as the varnish, so you have to decide if that will work for you.
I've used the Behlen (Qualasole) and Constantine's padding lacquer. Of the two Behlen's is easier, to use but takes longer to build. The stuff from Constantine's is more finicky about the thinning and weather conditions, but builds quickly. I've found that I can keep the pad sealed in a jar for many weeks when using the Qualasole, but with the Constantine's padding lacquer, I have to change the cover frequently or I get drag marks and an uneven sheen.
Rob Millard
http://www.americanfederalperiod.com
systembuilder,
I feel your pain! those are eactly the reason I've been such an advocate for shellac..
I can't brush worth squat but I can slop on overly thinned shellac easily and wind up with a decent finish..
Besides you don't need to wait.. 15 minutes after the first coat goes on you can apply the second.. 1/2 hr. later you can apply the third, an hour later apply the fourth and so on..
Never had a single problem with bubbles and the really great part about shellac is that the old can be so easily removed.. just flood it with denatured alcohol and wipe it off with a scotch brite pad.. Poof bare wood!
Oh, and scratchs disappear easily too! Just slightly dampen a rag with denatured alcohol and rub while saying abra cadabra (actaully any phrase works but kids love it)
frenchy,
I love shellac as well. But any finish is not optimal for all applications, right?
This project is a daily-use table top. It needs to be abrasion resistant, heat resistant, water and alcohol resistant, etc. Anf for a casual use table, a satin sheen , not glossy. I would say these are the most stringent set of conditions possible for a finish to meet. Have you actually used shellac for this application?
Actually, I don't think I have read anywhere a definitive finish recommendation (product type as well as finishing protocol like rubbing out to desired sheen) for a table top such as this. To the above conditions, add easy (for a novice finisher) to apply, and relatively quick (no waiting weeks or months to rub out). Also UV protectin to keep the dye from fading. In fact I'm sure I read conflicting advice on this last point from the usual suspects (Jewitt, Masachi, Dresdner, etc.. Some recommend water based dye for lightfastness. Others alcohol ).
Although I am most concerned with saving this project for my friend, I am also trying to figure out what finish and protocol I should use next time, for this type of project.
Dan
system builder,
The arguements in favor of shellac all seem to be designed especially for what you asked about.. the sole exception is alcohol ..
Frankly single malt scotch and fine wines belong on your pallet instead of on a table but should it happen all is not lost. First if you wipe it up quickly little harm will be done.. the next morning if you take a rag dampened with denatured alcohol and rub briskly the damage will disappear completely, If you have a hang over and want to wait a while that's OK, shellac is extremely patient ;-) having coasters around might have prevented it from occuring in the first place..
Water is another real myth.. My floor done in shellac had a airconditoner leak water on it for hours, when I stepped in it and realized I took a couple of towels and wiped it dry, no damage done. No whiteness (which is so easy to repair anyway) nothing!
As far as abrasion goes, shellac unlike it's imagined reputation is very hard. Probably the hardest finish available. Plus it repairs so easily, just use the rag dampened in denatured alcohol and scratches all disappear.. try that with any other finish.. No sanding no buffing nothing.. (saying abra cadabra is optional)
Satin is used because so many finishes wind up with a plastic look instead of the real depth and luster that shellac has.. There is a real reason shellac is used on antiques it's because it makes the wood just absolutely pop showing it's full glory without the gaudy plastic look of most finishes.. In My humble Opinion satin simply cammoflodges the plastic look it sure doesn't let the real beauty of the wood come thru..
Finally the ease that shellac can be applied made me a convert.. I can't brush very well, I was left with wipe on finishes and the limits of those eventually forced me to spray, yeh, air compressor, hoses, guns, airmasks, masking off areas dealing with over spray, clean up and etc.. I got pretty decent at it.. bought tons of expensive equipment etc. etc..
Then I tried shellac.. It really was the answer, so simple that I could do fine work with a barn painting brush or a mop! I couldn't mess up! Every mistake simply wiped up! Bare wood and start over in minutes! no sanding no buffing no problem.. Zinnsser even had premixed flakes already disolved.. stir for about 30 seconds and start to work!
No elborate clean up afterwards. Hang the brush up and let it dry, so what! The next time I used it I'd put it in some denatured alcohol and a minute or so later it was ready to use..
plus no finish is as safe.. you've been eating shellac since you were a child.. every pill and a lot of candy all has a shellac coating.. Plus just toss clothes that have shellac in them in the wash and they come out clean, free of shellac!
You're right, it's not perfect, don't shellac stuff for outdoor use (although the sawhorses I shellaced stuff on and have been outside for the last month show no real damage in spite of the heavy rains we've had lately)..
I do hope that you will try shellac the next time.. don't over think it,, just thin it out mop it on (and don't go over anything once you've brushed it) ask and I'll go over simple, error proof ways to do it.. it's really not as hard as the pros make it seem..
If the varnish isn't totally dry, adding a coat of poly isn't going to help. Giving it to your friend now will only be a problem if they place something hard and heavy on it, especially if the piece has any kind of edge on the bottom. The imprint will only go away with stripping and/or sanding. 7 coats of varnish be totally dry for some time. If you want satin, use the Scotch Brite, as recommended, but use a light touch and make sure you have good lighting.
What did you use for thinner- mineral spirits or turpentine? I was told that naptha is better and used that last time with good results. Long, slow strokes for varnishes.
Most woods won't absorb a finish with absolute consistency over it's surface, which is one reason to use a barrier coating. Bubbles are commonly from shaking the can or moving the brush too fast across the surface. Also, I have never heard that using soap and water on natural bristles is a good idea.
If you really want to give this table to the friend soon, stripping and recoating with something that dries hard quickly is about the only way to do it without ending up with imprints in the surface. Another thing- high gloss is usually harder and the hardness decreases as more additives are used for reducing gloss.
After seeing the photo, it seems that the coats were pretty heavy. That usually doesn't work well. Also, temperature/humidity play a role- what kind of weather did you have when you applied the varnish?
"I cut this piece four times and it's still too short."
Edited 9/22/2007 12:11 pm by highfigh
Highfigh,
My thinner was the recommended Behlen Reducer for their Rockhard Varnish. Although posters suggested using less expensive solvents (mineral spirits I think), I went "by the book" and used the Behlen product.
I did use barrier coats of 1 pound cut shellac, both after the dye step and after the glaze step, before using varnish. Using soap and water was recommended (after solvent) by Chris Minnik I think. Isn't he one of the finishing gurus? And a chemist to boot I think, so wouldn't he know? I'm sure I could provide the exact citation for this if you like. I really would like to believe that there is science behind finishing, rather than just black magic and folklore.
The finishing is being done in my basement workshop, which with the dehuidifier running this whole time, is about 70 degrees and 55% humidity.
Thx for your response,
Dan
Not trying to ruffle any feathers, just mentioning things I hadn't seen in any of the posts. The only times I used soap and water, the brush was ruined and I never store a brush without wrapping it in paper, as you indicated. Wasn't a cheap one, either. For the rest of the steps, it sounds like we would do them the same way, so the only other things I can think of have to do with brush strokes- maybe going back over the finish too many times with more air circulating that it wanted and possibly brushing too fast in some areas, causing bubbles. I know you want to give the table to your friend but, have you tried repeating the process on a smaller piece as a test?
"I cut this piece four times and it's still too short."
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