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Behlen Rockhard Varnish

systembuilder's picture

I am using Rockhard as a wiping varnish, as a 50/50 mix with Behlen Rockhard Reducer. So I guess it is basically a wash coat. My first time with Rockhard, and when the first coat was just put on and "wet" it is beautiful.

From what I've read here, I should get the same end result as if I were brushing it at full strength, just less varnish build up per coat. Therefor more coats. That's a good tradeoff to me because I don't have to worry about brush marks.

My question arises because my wood is curly maple. I've wiped on 2 coats so far, and these were over aniline dye, 2 wash coats of shellac, glaze and then another coat of shellac (1 pound cut). It appears that where I see the curly grain I am not building up a varnish layer. Why would this be, and will effect disappear after more coats? I can understand that the curl may behave like end grain (maybe one of you will tell me that it IS end grain). And maybe end grain is soaking up the finish, but then again I have 3 wash coats of shellac down already?

Any thoughts


rwdare's picture

(post #111354, reply #1 of 22)

The curl is very much like end grain. using a 50/50 cut it's going to take several coats to stop soaking in. Varnish is my preferred finish. Cut down with 400grit between coats to avoid winding up with a very thick finish.

When you eventually get it all filled and level, rub it out. You'll love the results. BTW while still filling the pores, just wipe it on full strength with a paper towel.


SteveSchoene's picture

(post #111354, reply #2 of 22)

It takes about three coats of a wiped on varnish to build an equivalent dry film to one coat of full strength varnish.  So just be patient--after 5-6 coats you will see real progress and begin to be able to level the surface without cutting into the stain layers. 

Test your finish on scrap, FIRST, or risk having to scrap your finish.

Jimma's picture

(post #111354, reply #3 of 22)

Maaaan, that Rockhard finish is thick! I bought some and used it on part of a tall clock without testing it first on scrap and found it to be way too heavy. It now sits on the shelf with other disappointing finishes. (My take on it only of course.)

systembuilder's picture

(post #111354, reply #4 of 22)


I'm learning to think that there are no bad fiishes, just sub-optimal applications. I was very hesitant to try Rockhard Varnish, and only did so on scrap at first, and at a 50/50 mix with the Reducer. So it went on easily, no brush marks, dries relatively fast because of how thin the layer is (I am putting on one coat every 12 hours), and it looks terrific when wet. Building up the thickness takes patience when wiped on, but I have the feeling (3 coats into this) that I will be very happy with the end result. Having said all that, I don't think I would use this on a vertical surface. I am using it on a tabletop. The base (apron and legs) is getting gel varnish (no drips or runs). Using two different products doesn't bother me, because the top will be left more glossy than the base, and the base is maple but the top is (very) curly maple so it looks different anyway.

I suggest you give the product a re-try, but in wiping consistency.


Jimma's picture

(post #111354, reply #5 of 22)

A tabletop is probably the best used for it. It did dry well and the surface was very glossy. (I actually dulled it down with steel wool or the like.) Maybe I'll try it again before its shelf life runs out, although most of my finishing tends toward oils. The clock needed a more traditional finish.

Jimmy's picture

(post #111354, reply #6 of 22)

Stuff brushes fine...just thin it a bit...mineral spirits will work as well as Behlins reducer.

Edited 9/9/2007 7:42 pm ET by Jimmy

SteveSchoene's picture

(post #111354, reply #7 of 22)

There are very few varnishes that don't need thinning these days because the manufacturers have removed thinner in order to comply with tougher VOC(volatile organic compounds) or HAPS (hazardous air pollutants) regulations.  Worse, they have to lie on the label and tell you not to thin because if they told you to use the thinner, the regulators would treat that as being just about the same as having the thinner in the can.  Think of it as a 10% (or 15%) bonus since you get that much more brushable varnish at the cost of a little reducer or mineral spirits.  It's not a sign of a poor product, but merely that the manufacturer decided to maintain the basic varnish by just removing thinner instead of changing it with additives or alternative solvents, changes with the potential to reduce quality.    

Test your finish on scrap, FIRST, or risk having to scrap your finish.

Jimma's picture

(post #111354, reply #8 of 22)

Thanks. Interesting explanation.

wolfman's picture

(post #111354, reply #9 of 22)

I used Behlen Rock Hard Varnish on an oak bathroom vanity I built for my house. The vanity top is also oak. I thinned the first two coats but applied another four full strength. I used a foam brush and the finish came out very smooth. When cured the finish lives up to its name. It is holding up well to the water and soaps, etc., that get splashed on it every day. Good luck.


vanity2.jpg65.57 KB
systembuilder's picture

(post #111354, reply #10 of 22)

I am 4 coats into the wiping varnish. The curly grain has finally started to have the same sheen as the rest of the wood surface. Even though I am wiping it on, there are some spots where I left it on thicker than other areas, and this is evident when the coat dries. Will subsequent coats take care of this, or do I need to be anal about sanding these spots down? I am afraid of seeing "rings" in the final finish. Also, do I need to use a tack cloth between coats after scuff sanding, or is vacuuming acceptable?



SteveSchoene's picture

(post #111354, reply #11 of 22)

The rings will disappear when you apply another coat on top.  So do your leveling soon, so you still have a coat or two to go. 

Test your finish on scrap, FIRST, or risk having to scrap your finish.

systembuilder's picture

(post #111354, reply #12 of 22)


Thank you. I wouldn't have tried varnish on this project w/o the advice given here. It is much appreciated. I plan on at least 2 more thinned coats.

What do you think about vacuuming vs. tack cloth? When I vacuum I still see remnants of th esanding "dust" Does this dissolve in the next coat of varnish?

Thx again,


SteveSchoene's picture

(post #111354, reply #13 of 22)

Varnish sanding swarf won't redissolve, it will just show up as lumps.  Best remove it.  (Shellac is a bit different, it's dust is likely to redissolve.)

Test your finish on scrap, FIRST, or risk having to scrap your finish.

systembuilder's picture

(post #111354, reply #14 of 22)

I am going to run out of Rockhard varnish before my last coat. PITA to drive all the way to the woodworker store to get more. Can I use another brand of varnish as my last coat or two on top of the Rockhard? Since Rockhard is only available in gloss, if I do this I'll get a satin varnish from the local store as the top coat since my friend wants a satin finish.


HowardAcheson's picture

(post #111354, reply #15 of 22)

Rockhard is just an oil based varnish. You can overcoat it with any other oil based varnish. Let it fully dry for 4-5 days, scuff sand it with 220 paper and apply your top coats.

Be aware that Rockhard is a very hard finish and the finish you substitute will not be quite as hard and durable.

BSzydlo's picture

(post #111354, reply #16 of 22)

Is it possible to thin Behlen Rockhard Varnish with mineral spirits or is there some special ingredient in their reducer that makes it preferable?

HowardAcheson's picture

(post #111354, reply #17 of 22)

You can thin it with mineral spirits but, to be safe, don't thin more than 10%. Any more and it will take longer to dry. Howie.........

Edited 9/18/2007 6:07 pm ET by HowardAcheson

systembuilder's picture

(post #111354, reply #18 of 22)

I thinned about 20% with Behlen's Reducer. The mixture was put in a jar and the first coat was brushed on. Waited 24 hours and appplied the second coat. The varnish was very noticeably thicker and harder to flow on. I assume the varnish reacted with the air in the jar. I thought I was being clever by floating saran wrap on top of the varnish, hoping to prevent it from reacting. I probably had the jar one fourth full of the varnish.

What should I have done differently? If I only mixed enough for the first coat, I still would have the varnish in its original can reacting with the air now trapped in it, right?

HowardAcheson's picture

(post #111354, reply #19 of 22)

When you thin and then stir an oil based varnish, you inject quite a bit of oxygen into the mixture. As soon as you do that, you start the oxidation process and the varnish begins to want to cure.

It is always best to just mix what you need. Pour from your can and immediately close the can. Then thin the material you poured out. Date the can and be prepared to discard any remaining material in 3-6 months. Finish is one of the least cost elements in your project and it's not worth the risk by being frugal with old finish. Never return partially used amounts to the original can.

The above is even more important with Behlen Rockhard as their varnish (and thinner) contains some fast evaporating thinner/solvent. These chemicals are what allows the Rockhard to dry faster than many other oil based varnishes.

systembuilder's picture

(post #111354, reply #20 of 22)


Thx for your response. I picked up fresh Rockhard today, and a new brush.

I sanded the bubbled coat with 320, which did not result in a perfect surface. I still had remnants of the hundreds of small bubbles. I flowed on a new coat, reduced about 25% with Reducer. I was hoping the new coat would dissolve or entrap the bubble remnants. It helped, but did not solve the problem.

Would you advise that I sand with 220 to get to a flat (in both senses of the word) surface before applying another coat? I feel like I already have all the thickness I need in the varnish coat. It simply isn't anywhere near perfect, necessitating more coats.

Bubble or not, when I sand between coats I do not get a uniformly flat or sheen-free surface. This indicates to me that the surface is not perfectly flat. Should I follow up block sanding with hand sanding without a block in order to scuff sand all the sheen off the surface before another coat is flowed on? I just don't know how anal retentive I need to be for proper adhesion of the new coat.

Thanks again,


HowardAcheson's picture

(post #111354, reply #21 of 22)

Lets go back to the beginning of the finishing process. The first thing you want to accomplish is to have a flat surface to start with. This is the result of proper sanding. ROS sanders frequently do not accomplish this. That is why flat sanding should be done with a 1/2 sheet orbital sander followed by hand sanding with the sandpaper on a sanding block.

Once flat, you apply the first thinned coat of your finish. Let it dry then flat sand it again with the hand sanding pad and 320 grit paper. Sand until it is uniformly flat. Now you can apply 2-3 coats of a lightly thinned top coat. In other words, you should work to the flat surface after your first coat. It becomes more difficult when you have more coats of finish.

Now, if you have hardened bubbles, you will have to aggressively sand the surface with 220 paper on a sanding block. Remove all evidence of the bubbles. Oil based finishes do not "melt" into hardened finish so you need to sand the surface flat. Once you sand out all the bubbles you can apply your final coat. How well it comes out is determined by how skillful you are in brushing on a finish.

Docx's picture

Sanded in finished behlen rock hard bar top varnish (post #111354, reply #22 of 22)

Can Behlen Rock Hard Bar top varnish be used to sand in a finish on a hunting rifle.  Will the slurry be as tough and waterproof as just filling the grain w the varnish