Durable Clear Finish for a Handrail
Durability and on-site practicality of various clear finishes suitable for handrails. May 7, 2007
Question
What is the most durable finish for an 80' interior cherry handrail that will have some traffic of company/kids? It needs to be something that will not wear easily. Water based or post-cat or other? I have the ability to have just about anything sprayed or wiped at our shop. Handrail is not yet installed. 12 box newels will need same coating.
Forum Responses
(Finishing Forum)
From contributor C:
I guess that a 2K urethane might be the ultimate... but I usually do a stain and polyurethane finish. I like to use a wipe-on where it is convenient and brush and wipe off on the tougher areas. Remember that the wipe-on coats are much thinner so that the wear areas need more coats for proper durability... 5 to 6 coats on handrails... Three on balusters. I do brush-on coats on treads and risers to get faster and deeper build.
Avoid most water base finishes for handrails or use them as undercoats because many are very prone to softening from oils on people’s hands. Most polyurethanes are much more resistant. CV's are probably good but usually overly difficult given the difficulties involved in the process... They may be a bit brittle too, for such a flexible installation.
From contributor R:
Thanks. I hadn't thought of 2K's and am not that familiar with them, but will look at it. I was considering post-cat Duravar as it's pretty tough, but I'm not sure if 3 coats would be enough for wear. This isn't going on treads or floor or balusters (iron), just the 12 cherry box newels and 80' of handrail. Any feedback on Duravar vs. polyurethane vs. 2k?
From contributor C:
2K urethane is extremely durable, but expensive and somewhat more hazardous/less convenient. Duravar is good stuff but I would prefer the ease of application of the polyurethane over either of these and have found it quite satisfactory in long term performance (basically 0 complaints over many years of use). Make a nice job of it and add an extra coat or even two for more durability and your customers will love it for many years.
From contributor M:
Duravar will suffice, however it is a nitrocellulose product and not quite as durable as MLC's Krystal or CV200 (they are basically the same but CV200 is a low-odor formula, and superior in my opinion).
Second, on any post-cat conversion varnish product like Duravar or CV200, anything more than 3 coats is asking for trouble - conversion varnishes do not like to be piled up. Given six months to a year, it may begin to crack.
The 2K polys are probably your best bet. You can basically pile them as high as you want. You can use stain under the line of 2K poly that MLC offers if you are using their stains. The trick with 2K poly is to catalyze only what you will spray in about 20 minutes, for it starts to thicken by then and is difficult to spray. Otherwise it is a fantastic product that I recommend highly. It's called Eurobild. I would use the satin sheen for two reasons: it doesn't show scratches as easily as gloss, and you use the same catalyst for satin as you do the sealer (the glossy sheen requires a different catalyst, i.e., more money). You will need the Eurobild Sealer, Eurobild satin sheen, Green Catalyst (it isn’t actually green), and some Eurobild reducer to thin it. The catalyst ratio is very easy: two parts of Eurobild to one part catalyst. Much easier to measure than the 10% rule of conversion varnish. If you are doing a natural color (no stain), ICA makes a great 2K poly as well, but I don't think you can stain under them.
From the original questioner:
There will be a slight stain put on this before topcoat, so I'll ensure whatever is used is compatible. I was under the assumption that Duravar was more durable than the MLC Krystal so I'll double check that. I know the Duravar can't be piled more than 2-3 high and I wonder how durable that would be compared to the same number of coats of 2K. I don't want it to get too thick, which sometimes doesn't look too good. We are going with satin, as it shows less wear. I'll go look at the Eurobild. Thanks for the tip. So it sounds like Duravar, Krystal, polyurethane or 2k are the best choices?
From contributor Z:
We just use waterborne lacquers in the houses we paint. It is more than tough enough and stands up really good. Easy to use, real easy to touch up after install. No chemicals and no off gassing in the house for a month. If this was an institutional railing that saw high traffic like a school, a mall, or something, I'd recommend a urethane. Lacquer (nitro or WB) will give you a nice light finish without that thick plastic look to it.
From contributor A:
Oil base poly is very tough stuff. There are two reasons shop guys don't use it. It takes 8 hours to dry and you have to sand between every coat. On a job site, why not use regular poly? The stairs that the handrail is attached to will most definitely be coated with oil based poly.
Contributor C, I would love to see some evidence of waterbornes being prone to "sweaty hands."
From contributor C:
I have done many repairs on handrails and cabinet doors (where the frequently handled areas are). In most cases I believe these finishes to be NC lacquers or water base finishes. I very rarely see these effects on CV or polyurethane finishes. I have never encountered the same problems with my own water base finishes... so there are products available that are not particularly vulnerable to these hazards. Because the OP is not doing this on a regular production basis, I suggested oil based polyurethane as it is a favorite of mine for handrails (and widely available in pretty reliable formulas). I really think that it is much easier to handle than water based finishes for handrails (though most of mine are done on site). I say this even though I use water based finishes for close to 90 percent of my finishing projects. I think one needs to know a specific water base finish well to trust it for such projects. I am also quite sure that it requires a higher skill level to get fine results with water based coatings.
