Advangages/disadvantages of TYPES of clear coat?

[ghmerrill]

I'm now part way through stripping my 1947 Olds Standard so I can relacquer it. I've read a number of threads on here that have good information in them and recommendations for various products. But I'm unclear on the relative advantages and disadvantages of different TYPES of lacquer: nitro, acrylic, urethane/polyurethane, ... ?? Not so interested in epoxy.

I'm kind of leaning towards acrylic because of experiences I've had with it in other areas, but I'm not sure if it would be among the best choices for brass. I know that this doesn't deserve a lot of hand-wringing, but I'd rather not make an obvious misstep.

Any thoughts will be appreciated.

[WGWTR180]

Are you doing this yourself?

[ghmerrill]

But of course.

[hornbuilder]

What is your issue with epoxy? Access to an oven?

[ghmerrill]

Well, certainly I'd need an oven for a baked on epoxy. But more generally -- and perhaps from ignorance -- the whole epoxy approach seems more complicated (certainly if I have to bake it) and fraught with pitfalls than I think I want to deal with -- for any gain I might enjoy from it over other approaches. Also, it seems to me (???) that epoxy finishes tend to be thicker than alternatives.

But I'm open to argument there.

One issue is whether I should just go with an "indoor" coating or instead find one more suitable for outdoor use. (Now we're getting a bit into the -- perhaps senseless -- handwringing.) In general, for anything I might use outdoors, I want UV resistance. And I can imagine occasions (outdoor concert, etc.) where I'd have the horn outdoors. Maybe two or three times a year. But does that justify going to the length of a UV resistant lacquer? Maybe not.

I've been eyeballing some of the Krylon products (Acrylic Max, Gallery Series Artist, Color Master). Also Permalac NT Clearcoat-- although that's pretty expensive, and it's difficult to tell if I wouldn't do as well with something more mundane.

One product that I've used and like quite a bit for its ease of use and result is Minwax Helmsman Spar Urethane, but it doesn't appear to be a good choice on untreated metal.

I guess I'll be happy to pick one of the many possibilities as "good enough". But right now there are a lot of possibilities. Now you see the handwringing.

[BGuttman]

One problem is getting a coating that is thin enough to allow the instrument to vibrate properly and durable enough to protect against oxidation.

This is the reason cellulose (and nitro-cellulose) lacquers as well as epoxy lacquers have been so popular. It's easy to thin the cellulose or epoxy lacquer to provide a very thin coat (under 1 mil/ 25 microns) and still have protection.

My experience with acrylics (particularly UV curables) is that they cannot be thinned properly and result in a rather thick coat.

I see that urethanes have been popular on student instruments where the durability of the coating trumps all and the fact that the horn doesn't sing properly won't be noticed. Again, my experience with urethanes is that it is difficult to thin them to provide a proper coat.

[ghmerrill]

One problem is getting a coating that is thin enough to allow the instrument to vibrate properly and durable enough to protect against oxidation.

Yes!

My experience with acrylics (particularly UV curables) is that they cannot be thinned properly and result in a rather thick coat.

I see that urethanes have been popular on student instruments where the durability of the coating trumps all and the fact that the horn doesn't sing properly won't be noticed. Again, my experience with urethanes is that it is difficult to thin them to provide a proper coat.

Thanks. This is what I was wondering about.

So are there 1-part spray-can epoxy lacquers available to me? Or should I just go with the nitro lacquers?

An alternative would be to abandon lacquer entirely and go with a (Renaissance?) wax finish. That might be worth a try initially since it's easy to "reverse".

[hornbuilder]

The biggest issue with most domestic/commercially available "lacquers" (in " " so as to cover anything that may be considered applicable to the project) is durability. Even the air-dry Niklas products, aimed specifically at use on brass instruments, is not terribly durable. Sure, you can apply a very thin coat, but that obviously reduces the durability, too. The Niklas epoxies (which I use in my shop) can also be applied very thinly, but have considerably better durability than any air-dry finish.

[ghmerrill]

I take it that by "durability" you mean protection from surface marring, scratching, etc. And I guess that's not high on my list of desiderata. It might be higher if this were an expensive horn, if the surface were immaculately free of little signs of history, and if it were my primary (or even secondary) instrument. But I've been pretty good at protecting my instruments from the feet, elbows, and stands of woodwind and high brass sections in the community bands I play in. I do want something that doesn't require ongoing and rather constant maintenance. I already have a 100 year old silver tuba in that role. But reasonably "periodic" surface maintenance is okay, and comparatively, a tenor trombone is almost zero effort to clean and polish as needed (if needed).

I really appreciate the insights I've gotten here on lacquer finishes. I think what I may do now is to go initially with the Renaissance wax, and see how that goes. If it turns out to be a pain or not work well, it will still be easy to take the lacquer step later. All for a 76 year old horn that cost me $125.

[Doubler]

I've had surprisingly good results with Rust-Oleum Specialty Lacquer (available at Home Depot). YMMV. Preparation, cleanliness, dust avoidance, technique. and experience are all crucial to a good result, as is keeping the finish waxed after it cures. Spraying the inside of the bell flare is a bit tricky, as the spray does not want to go far enough in before drying into orange peel. Finding a way to create a slight vacuum to draw the spray in can help.

[ghmerrill]

Nice hint on the bell problem. Creating a pressure differential in the bell should not be a problem for me. I have a 2HP dust collector system that I can set up with a kind of funnel hood horizontally behind the bell. A little testing, and that should do it.

One other thing I neglected to mention is that I'm planning on applying one or more patinas to the horn surfaces -- which I think would make for a more stable finish, either waxed or lacquered. But this is all a bit of an experiment.

[hornbuilder]

Fair enough, re your requirements. Of course I'm speaking from a makers perspective, who wants to provide customers with a long lasting, durable finish that will hold up over time. So my requirement/expectation is not the same as yours.

Re the inside of the bell, make sure you have the tuning slide out of the horn. That way the air has an exit path. Will you be using a spray gun, or spray can??

[ghmerrill]

Fair enough, re your requirements. Of course I'm speaking from a makers perspective, who wants to provide customers with a long lasting, durable finish that will hold up over time. So my requirement/expectation is not the same as yours.

Yes, definitely different situations. This is a 76 year old horn (made in the same year I was born) that I got for $125 (including an aftermarket hard case), and has a somewhat unusual appearance (the serpentine braces). I had a few dents removed, the bell flare de-dented, and the slide straightened. Mostly as a project I just want to make it look a bit better. It still has some minor dings (not visible unless you really look closely) that aren't worth addressing. It's just for fun. I may play it in small groups now and then, and just for myself. Probably won't replace the 12c Kelly mouthpiece I'm using on it because it will be "good enough" and I sanded the shank down so that it actually fits the leadpipe taper.

Re the inside of the bell, make sure you have the tuning slide out of the horn. That way the air has an exit path.

I can't stop laughing at this. The image in my mind is just hilarious. It's like "The Three Stooges do trombone repair." But you're right to offer the caution. I do know people who would make a mistake like that.

I'm just going to use a spray can. I'm not sure the gun we have could be set up for this, and if I end up doing a patina/wax job on most of the horn, I may not be spraying much at all (possibly just the crooks, braces, and a couple of other places -- a lot of masking tape may be involved). I'm still thinking about possibilities there.

I think it will come out well -- and not be anywhere near the effort of cutting that 1924 tuba down to A=440.

[BGuttman]

Gary: Is this a Getzen Dude?

[ghmerrill]

No. I think that might fall into the "collector's item" category. It's a 1947 Olds Standard. Apparently they made those with the "serpentine" braces for a couple of years ('46, '47). Until recently I thought it had been relacquered at some point and maybe the inners replaced. But I've become convinced that it's original.

The description of the braces as "serpentine" is misleading. They're not really at all snaky. I'd refer to them as a kind of thin "hourglass".

[ghmerrill]

Here's a picture of it before I started on the stripping ...

viewtopic.php?p=226164#p226164

[ghmerrill]

I just did a survey of our collection of paints/varnishes/lacquers/solvents/adhesives/... (but just the spray can ones!). My wife is a HUGE fan of clearcoats for the various "projects" (indoors and outdoors) that she gets involved in. She'll clearcoat anything. She clearcoats everything. If you're standing still around here, there's some danger that you'll be clearcoated.

So there were two varieties of Rust-Oleum, a Valspar, Minwax fast-drying polyurethane, and (!) Deft "clear wood finish" semi-gloss (nitrocellulose). I don't think I'll be running out to buy anything else.

I have a kind of fatal attraction to the poly, but think I may just go with the Deft so-called "clear wood finish" since it's actually intended for metals as well, of course. The can is mostly full. I suspect she hasn't used it because she decided it isn't "tough enough".

[ghmerrill]

Well, I was gearing up to strip the bell, but ...

I put the horn together and the stripped hand slide and tuning slide look great. But I don't think I can bring myself to refinish the bell. There's nothing really wrong with its appearance: the narrow end has darkened a bit and there are a couple of small oxidation areas near the rim (looks like one may be acid bleed), and there's some darkening and minor "blemishing" under the lacquer between the front and real bell braces. But otherwise, no real issues, and no wear on the lacquer there. I don't think I could do any better in terms of appearance than that "old gold" shade of the bell section. It contrasts nicely with the polished brass of the slides now. So I think I'm just going to strip the remaining braces and the gooseneck, polish and lacquer the areas I've stripped, and be done with it. It is, by the way, a Los Angeles Olds.

Now I just have to be careful to mask off the bell so I don't mess it up while stripping the rest.

[ghmerrill]

Here's the semi-final result. Semi-final in two respects: (1) I may at some point in the future decide to refinish the bell. But right now I'm liking it; and (2) I think I need to go over the new finish lightly with some automotive clearcoat polishing compound. That can of Deft I used wasn't a full one, and had been sitting around for quite a while. As things progressed, there were a couple of times when it sputtered a bit, and so some of the new surface isn't entirely smooth. Not globby or runny. Just a tiny bit rough. I think a bit of rubbing will bring that down.

Otherwise, I like the result. I think the old bell contrasts nicely with the new semi-gloss finish, and it's pretty much what I was going for. In the photo, some of the newly refinished parts (top of tuning slide and the braces up there) are actually reflecting the darker hue of the bell. The new sections (including the entire hand slide and all the braces) are bright yellow (like the gooseneck).

Peculiarly, the horn seems to play better. I can't think of any reason it should, but it seems to. A bit more lively and responsive. And previously I just couldn't get the pedal notes to speak. Now I'm good for the Bb, A, Ab pedals. And it just sounds a little different. Probably just a psychological effect.

Refinished Olds Standard.jpg

[ithinknot]

Looks great. And leave the bell alone - "age-appropriate red" always looks good.

Braces are fun. Are they all hollow, or is the tuning slide/rear bell solid by way of counterweight?

[ghmerrill]

I think they must be hollow. While I can live with the horn absent a counterweight, it would be more comfortable with one. It's slide heavy. Of course, the normal sort of easily available bolt-on counterweight won't work (at least unmodified) on those braces! And I don't like the idea of clamping one onto a brace anyway and ruining the appearance.

I have a couple of plans to add one and I think will experiment with one that I can sort of clamp on (cable clamps) to the tuning slide before doing anything permanent. Otherwise, I do have a brace/flange base sitting around that I could solder to the inside top of the tuning slide, add a stud to, and then put a counterweight of some sort on that. If only I could get one of those Bear counterweights that Olds put on some horns eons ago. I could probably make one, but it's quite a bit of effort.

Time will tell.

[BarryDaniels]

That looks really good. What kind of abrasives did you use?

[ghmerrill]

To strip it? I used Citristrip -- which seemed to work to at least some degree. Then steel wool (#000 and then #0000). Polished with Brasso and then went over it again carefully with the #0000 steel wool). The result was pretty shiny, but not buffed. Since I knew I was going to use a semi-gloss, I didn't bother getting involved in any type of buffing, even though I do have a set of good industrial abrasives for brass and soft metal. There were enough little surface imperfections in it after 76 years, that going for a mirror finish seemed silly -- and it wasn't what I wanted anyway.

I was REALLY careful about cleaning the surface before lacquering -- including a couple of wipe-downs with denatured alchohol.

[BGuttman]

For a counterweight Olds used to attach a solder-on post to the tuning slide bow and a weight would go on that. See the Ambassador for an example.

[ghmerrill]

For a counterweight Olds used to attach a solder-on post to the tuning slide bow and a weight would go on that. See the Ambassador for an example.

Yeah, that's exactly what I'm thinking of. If I solder on a flange I have (from a junk low-end parts trombone), I can either put a simple post or a threaded rod in it and the put a weight on it. There are some simple screw-on "couplers" that would probably work well as weights.

[davdud101]

Hey Gary, it came out fantastic! I'm wanting to do something sort of similar, I'd like to try a satin lacquered finish on just the outside of the bell flare and leave everything else in standard lacquer. Trying to find a cheap Yamaha 354 or something similar (like $60 or less) to experiment on.

You went with the Deft after all?

[ghmerrill]

Honestly, the picture is a bit better than the horn is close up and with a magnifying glass. I'm still not sure how well the surface has come out. There's a whole complex issue of the "orange peel" phenomenon that I think I might be seeing to some degree (though I honestly don't care about it). However, having at this point put some time into researching that, if I were to do this again I'd likely use a gloss lacquer and then "satinize" it myself in one way or another. Apparently what's done to create the satin version of a lacquer is one of the things that invites orange peel in the finish. The auto guys go nuts about this -- and observe that even high end auto makers (Ferrari is mentioned) continue to turn out production cars with the dreaded orange peel.

[BarryDaniels]

Satin lacquer can be created in two ways. The first is adding a flattening agent to the lacquer. It looks kind of milky and is comprised of stearates that reflect the light in different directions, creating a semi gloss look. Add more to the mix to make the finish more dull. More gloss lacquer is usually applied on top of the satin lacquer to provide a protective layer on top. I have never had an issue with the flattening agent causing orange peel. Orange peel is usually the result of too much air pressure coming out of the spray gun.

The second way to create a satin look is to spray gloss lacquer and then sand the final coat with fine sandpaper, but fine steel wool would also work. This has the advantage of not having to add anything to the lacquer, but if the lacquer gets handled a lot, the sanded surface can wear away revealing the glossy lacquer underneath, usually in an uneven pattern.

I finish guitars and lately have been doing the sanded version on the back of my guitar necks because the hand will slide on the neck more easily. And once the gloss comes back, it can be lightly sanded again to renew the satin.

[ghmerrill]

Thanks. I have to see how this has really come out before I do anything else. I'm inclined to attribute any issues with it primarily to poor spraying technique. In general it looks pretty good, but the effect in a couple of places is "non-uniform." It does seem to pass the "10 foot test". So I'm going to try not to obsess about it.

[BarryDaniels]

I think the finish bumps isn’t poor technique, but just the result of using a rattle can finish. They tend to spit out big drops of finish instead of laying down a finely atomized finish like a good spray gun does. One way to fix this would be to sand the finish with some really fine sandpaper (like 800 grit) and then spray another coat. But you might want to use a fresh can because there are likely to be less coagulated droplets in a new can, and the can’s pressure will be higher to provide better atomization. Or just leave it as is.

[ghmerrill]

One way to fix this would be to sand the finish with some really fine sandpaper (like 800 grit) and then spray another coat. ... Or just leave it as is.

This is the plan.

Thanks for the grit suggestion. I need to drop by the local Klingspor tomorrow (I checked that they do have the Deft in stock). I think I may have 600 paper but not 800. I do have 1200 and 2000.

[BarryDaniels]

600 would be fine. I would use it with some soapy water. Be careful not to sand through the finish because one coat is not very thick. I usually wrap the sandpaper around a "Pink Pearl" eraser which provides just the right combination of rigidity versus flexibility to help level the finish.

I apologize if I am coming across as a know it all, but this is one subject that I am very familiar with whereas my knowledge about trombones can barely fill a 12C mouthpiece.

[davdud101]

Just realized I mighta mis-termed - not sure why I said satin lacquer, what I meant was a brushed or scratched/matte finish under clear high-gloss lacquer.

My few experiments finishing guitars I think would get me close enough to a reasonable gloss finish... I generally apply 3 coats per day, and depending how things are, I’ll give each coat 30m-1hr and then sand 1000 or 1200 grit in between, leaving the lacquer dust to remelt between coats.

Whether or not I skip any sanding between any coats, I DEFINITELY sand before my final coat. After all my coats are down, I give it 2 weeks to cure. Lastly, I polish it to a mirror/bright gloss with Meguiars. Curious how many coats I should do on a horn, knowing the thickness affects the actual vibration of the bell. I'm used to doing really wet, heavy applications on guitars, but I doubt that will fly on a horn. Definitely open to changing my process if you guys think any of these steps won't work

I’m really glad I just found a bundle of beat up horns (a Yamaha 354 and 2 Bundys) to practice on for super cheap... Goal is to perhaps put some money into the Bundys to restore them to playable condition, then practice my finish process before doing the 354 bell (or doing my “real” 354’s bell and keeping the new one as a backup)

[ghmerrill]

I apologize if I am coming across as a know it all, but this is one subject that I am very familiar with whereas my knowledge about trombones can barely fill a 12C mouthpiece.

I'm perfectly to take advice from a "know it more than I do."

[ghmerrill]

I’m really glad I jus found a bundle of beat up horns (a Yamaha 354 and 2 Bundys) to practice on for super cheap...

If you want really super cheap, but possibly some interesting and restorable horns ...

https://shopgoodwill.com/categories/brass

[davdud101]

I’m really glad I jus found a bundle of beat up horns (a Yamaha 354 and 2 Bundys) to practice on for super cheap...

If you want really super cheap, but possibly some interesting and restorable horns ...

https://shopgoodwill.com/categories/brass

Thanks Gary! I haven't used shopgoodwill in many years, but I *almost* got a Conn Coprion from here once, and I think I actually has a YSL 352S from here back 5 or 6 years ago (or maybe that was somewhere else....)
In any case, I'll keep my eyes peeled. Have been hoping to find a nice 354 in silver plate, but they're way pricier than any standard 354/200AD's out on the streets

[ghmerrill]

Well, you have to catch things like that when you can -- which requires special vigilance.

However, I did see this when just looking about a few days ago. I have no idea, what it is, and the picture is a bit peculiar since it appears to have been taken on a bed that someone is actually sleeping on at the time. But it might be worth investigation.

https://charlotte.craigslist.org/msg/d/ ... 48115.html

[ithinknot]

I have no idea, what it is, and the picture is a bit peculiar since it appears to have been taken on a bed that someone is actually sleeping on at the time. But it might be worth investigation.

https://charlotte.craigslist.org/msg/d/ ... 48115.html

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[Executive Producer Dick Wolf]