Durable, Repairable Finish for Small Items
What's a good finish for a small wood item that may get rough use (such as wood cups for headphones)? It's a tough straddle. November 29, 2014
Question
I make wood headphone cups. Thus far, I have used shellac and an HVLP touchup gun. You can assume this is the extent of my finishing experience. I recently switched to an airbrush, and I'm trying to take my finishing more seriously. I'm about to sell a complete headphone, which means I can expect these things to be abused by everyone. I've always marketed the shellac as being a traditional instrument finish that is repairable by any skilled finisher until the end of time. Nitrocellulose lacquer seemed like the obvious next step, but I've heard tales of its softness for the first few weeks. Does anyone have any suggestions on what process, system, or product to use for my headphones? The photo below is BLO, blonde shellac and deft spray lacquer.
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Forum Responses
(Finishing Forum)
From contributor J:
If you have a lathe and can spin and polish the headphones, the friction finish that can be accomplished on a lathe is far better than anything out of a sprayer. Save for a high build polyester finish.
From the original questioner
We try to do as many parts on the lathe as possible but this is not always an option. Do you have a suggestion for a friction finish? I know nothing about them.
From contributor M:
Friction polish will look nice until you use it more than twice. It's literally the worst finish I've ever seen for durability. Spray them with pre-cat lacquer. There are a dozen or more brands out there easy to find. Thin it with something like butyl acetate or other slower-curing finish. Pre-cat is a lot more durable and quite user friendly. I wouldn't spray them with shellac or nitro lacquer. Both are more durable than friction polish, sure, but still not nearly as durable as pre-cat. You're going to need chemical durability more than physical scratch resistance. Trust me, in my early woodworking years I made several hundred fountain and ballpoint pens. I sprayed them all with conversion varnish, and now seven years later they still look quite nice as long as they are cared for properly. I don't suggest conversion varnish for you necessarily but it can be made to work. I'd try pre-cat lacquer first, a bit more user friendly.
From contributor F:
Durable and repairable is sort of an oxymoron when talking about finishes. What makes a finish easily repairable is weak resistance to solvents and therefore itself. This makes blending in repairs easy which is why furniture manufactures and re-finishers love it. You have to weigh how much repair work you will be doing when choosing to stay with a shellac or nitro finish or stepping up to a pre-cat or something stronger. Pre-cats can have varying resistance to solvents so one type will be easier to repair than others. But with the size of your headphones, I would not worry too much about blending anyways. Just scuff and re-shoot the whole piece.
From the original questioner
I picked up some Sherwin Williams T75F16, CAB acrylic lacquer bright rubbed effect. I wanted gloss but they only had the bright rubbed in stock. I found that strange, wouldn't people want to add flattening agents instead of just having it already in there? It seemed to work well, it levels nicely, and it dries very fast. I think I'll have to put an order in for the gloss, or wait until the flattening agent settles in my can and skim off the top.
From contributor M:
CAB is more durable (generally) than standard nitro lacquer but is still less rugged compared to pre-cat lacquer. I don't think it gives as much color pop either. The reason people want to buy the can of clear with the flatting agent already in it is because most production shops need the same sheen, over and over, as convenient as possible. The manufacturer is far more capable of making a consistent sheen than we are in a shop. Plus, dosing out flatting paste and mixing it is one added hassle. I've done this before, didn't care for it at all. We had a kitchen that the customers wanted "extra dull", so we took a risk and overdosed the pre-cat. It worked, but was a big hassle.
From the original questioner
To contributor M: I'm finding the CAB to not be what I want. Too soft and the flattening agent gives the wrong look for this product. Can you recommend a pre-cat that I can buy in gallons?
From contributor A:
Try Mohawk products. They have pre-cat lacquer that finishes great and it also comes in an aerosol can for small projects - I think it's perfect.
From the original questioner
I'm tempted to go with their waterborne pre-cat for health and safety reasons. What am I giving up if I purchase their waterborne over their regular pre-cat? My (very limited) experience with waterbornes is that they always look dead and boring. This is the problem I'm having with my CAB lacquer, although it may simply because it's not a true gloss product.
From contributor F:
Water based and CAB Lacquers are both water clear finishes, meaning that they have no yellow or amber tone to them. This can produce a rather uninteresting look when used as a stand-alone finish with no stain. CAB Lacquer is also no more durable than Nitro Cellulose lacquers, it's only real advantage is being water clear when used for applications that call for it, as in clear coating over light colored paints or stains where a yellowed appearance is not desired. An amber toned finish can help pop the grain and lend warmth and personality to a finished when used on natural wood or over dark colored stains. A good distributor should be able to make you a pre-cat that is the same color as an amber shellac by adding a bit of dye to it or you can do it yourself if you have the dyes.
