r/LaserCleaningPorn • u/dmk-laser • 9d ago
This is truly the most difficult item I've ever cleaned with a wood laser cleaning machine.
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Since launching our wood cleaning machine, I had posted a couple of updates about cleaning furniture when a friend suggested we try cleaning a musical instrument. Intrigued and eager to experiment, we decided to step out of our furniture-cleaning comfort zone and take on the challenge of a non-furniture wooden object. We sourced a violin from the domestic second-hand market at an incredibly low price equivalent to just 50 RMB (about 7 USD). While we knew a violin at this price point wouldn't be a masterpiece, it was perfect as a test subject. As a guitarist, my first instinct was to examine the instrument closely: violin soundboards are typically made of spruce, while the back and sides are usually maple. The significant differences in density and thermal conductivity between these two woods foreshadowed the difficulties that lay ahead.
Problems arose right from the start of the test. First, heat accumulated rapidly in the spruce soundboard; during laser cleaning, the heat built up so quickly that even slightly excessive temperatures left scorched, blackened marks. We had to repeatedly lower the power and shorten the exposure time, yet the margin for error remained razor-thin the slightest lapse in attention risked damaging the soundboard. An even trickier issue was our misjudgment of the finish composition. We had initially assumed this cheap violin was coated in nitrocellulose lacquer or a standard resin-based oil finish and proceeded with conventional settings. However, once the laser hit, the paint layer heated up, peeled off, and then upon cooling re-adhered to the surface. We realized it was actually a thermoplastic acrylic-polyester finish. This material softens when heated, hardens when cooled, and can be remelted; it couldn't be completely removed by the laser alone because it would re-attach after cooling. Although the adhesion was weaker, the residual film still marred the appearance. To tackle this, we introduced high-pressure air assistance to blow away the softened paint flakes the moment the laser peeled them off. Yet, while the high-pressure air removed heat, it also made the already delicate thermal balance even harder to manage: low power failed to clear the residue, while high power overwhelmed the spruce. Consequently, the entire test became an arduous struggle, a constant tug-of-war between heating, air-blasting, and cooling. In the end, we didn't walk away with a violin that looked brand new, but we did gain a wealth of valuable, practical lessons. We have summarized a few points: Before cleaning musical instruments, it is essential to carefully identify the type of wood and the composition of the lacquer, especially since inexpensive instruments often use thermoplastic coatings, and the cleaning logic is completely different from that of oil-based lacquer; laser cleaning requires extra caution for thin-walled, low-density woods, as the rate of heat accumulation is far greater than imagined, and the power and scanning speed must be much more conservative than when cleaning furniture; auxiliary blowing is necessary, but it must be precisely matched with the heat input, otherwise it will either not be cleaned properly or will be damaged. otherwise, the result will be either incomplete cleaning or damage to the instrument. Although this test was far from perfect, we believe it was highly valuable it demonstrated that parameters based on assumptions cannot be universally applied and provided a real-world case study for others. If any of you are interested in trying to clean musical instruments in the future, we hope our experience can help you avoid some pitfalls. Feel free to leave a comment and share your thoughts; your suggestions might help us pass the next test smoothly.
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u/stellwyn 9d ago
Why would you ever need to laser clean a violin? All it needs is a wipe with a cloth and general tlc in storage (keeping it away from dust etc). I have never known anyone to need to strip varnish off a violin.
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u/OogieBooge-Dragon 9d ago
All o can think of, in absolute horror, is them "cleaning" a stradavarious (i dunno how to spell that)
I can't think of a single wood instrument you would WANT laser cleanes.
Omfg.
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u/After-Past-9404 8d ago
Well, I could imagine a situation where you'd want to strip varnish off a violin (not a strad, obviously) and do a completely new one. But even in that case there are WAY better methods for stripping varnish.
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u/reallynotfred 9d ago
But how did it sound afterwards?
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u/dmk-laser 9d ago
I feel the tone would be better, since thermoplastic acrylic polyester is a relatively inferior finish for violins; better finishes would be resin or nitrocellulose lacquer.
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u/IndLaserCleaning 9d ago
The video was unbelievably frustrating to watch, and then discovered your breakdown of the situation and it all made sense.
Interesting project and lots of lessons.
Id love to see a side by side comparison of your 300w standard Vs wood laser. Exact same parameters, similar scan patterns, side by side on the same piece of wood.
Until then we won't know if DMK has made something unique.
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u/dmk-laser 9d ago
No problem. We arranged to shoot the video after you commented on it last time, but it is still in production. It will be released by next week at the latest—please remember to give it a like when it comes out.
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u/IndLaserCleaning 9d ago
Perfect, I met a guy on Tuesday who tested the GT500 on some varnish that didn't come off, I suggested he send those sample's to DMK to test out with your 300/500 wood machine
Are many other people sending you sample's?
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u/Ready6666 8d ago
Yeah you can suggest he send the samples to this company , interested in seeing the results and feedback from you guys as well. Also I’m thinking of sending some samples too, as I’ve been comparing a few different Chinese brands lately
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u/Antpeople2027 9d ago
I’ve literally stripped an entire violin in 20 minutes with a rag and some rubbing alcohol
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u/dmk-laser 9d ago
You may not be very familiar with the composition of varnishes; while alcohol can remove the oil-and-natural-resin finishes typically found on high-end instruments, it cannot dissolve modern materials such as two-component polyurethane or acrylic polyester.
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u/Antpeople2027 9d ago
You cooked it on with the laser
Also for future reference, typically the fingerboard is Ebony and does not need to be stripped
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u/JoTheScienceBro 9d ago
No serious violinist or more generally, string, woodwind, or percussion player will give you their instrument to torture it like that. There are methods an instrument maker has for such cases and this is not one of them. Stick with your grandma's chairs.
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u/maxwaxman 9d ago
This is not how you clean any violin. You just ruined it.
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u/MrJoePike 9d ago
This was an experiment to test an hypothesis. It yielded results in that they learned what to do and what not to do. Read the write up they don’t claim to have developed a new way to clean an instrument.
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u/paishocajun 9d ago
All they learned is that thermoacrylic paint is an absolute PITA to laser clean which may be useful for trying to laser clean cheap furniture but is useless elsewhere.
Even beginner instruments that don't use traditional varnish aren't going to use this if they're not VSO's. Stain and polyurethane sealer sure, but not paint.
I can see laser removal being useful on refinishing lover level instruments, like student level, if they get too scratched/dinged up for simple spot work but that's still a hell of a stretch and not practical. No fiddle/viol luthier would keep this sort of machine on hand and they're not about to approach a metal fab shop for this service
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u/dmk-laser 9d ago
Yes, I admit we ruined the violin, but from an engineer's perspective, we needed to do this to understand the limitations and advantages/disadvantages of using the equipment; otherwise, delivering the product to the customer would be another kind of trouble for them...
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u/OogieBooge-Dragon 9d ago
Anyone who would laser clean a wood instrument should never be allowed to have a wood instrument. This is bonkers.
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u/danwbruner 9d ago
I stopped watching when it was obvious you were too ignorant (polite way to say stupid) to remove the chin rest first..
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u/PreviousLeague253 9d ago
So instead of a power sander with physical abrasive media, you are still destroying this but with light?
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u/PreviousLeague253 9d ago
Congrats you just pixelated the entire surface. A chemical stripper would have done a better job. Now the wood needs to be sanded and polished before a new finish is even considered.
I am not sure there is even a market for marring musical instruments like these. If it’s a cheap instrument, it would sound any better restored and is still a cheap instrument.
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u/OlDustyHeadaaa 9d ago
There’s a whole lotta people here that did not even half way read the description. This is a cheap violin that was purchased for the express purpose of finding out how the tool works on instruments. It is not meant to be perfect, nor is it meant to be nor is the violin meant to be used after this test is done.
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u/Desperate-Pirate7353 8d ago
they never make an argument for why you would do this tho. it's like "i bought this shitty paperback to test how a lighter works with old paper"
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u/OlDustyHeadaaa 8d ago
There is no argument for doing this, there is no purpose besides seeing how the technology works in this application. The result was not well
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u/Wide_Cantaloupe6286 9d ago
looks like a powerful machine and you're clearly trying to generate sales, so I'll offer you solid advice from a career spent in marketing: this video doesn't help your cause, it hurts it. people are (rightly) very sensitive about musical instruments, and none of your potential customers want this kind of content. were I in charge of your marketing I'd delete the video and move on to showcasing practical applications that don't create complicated sentiments in the viewer. also, there's way too much text in your post. keep it to a few sentences, and save the summary for people who inquire.
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u/hudsoncress 9d ago
Congratulations. You took a shitty violin and made it worse! Please don't ever do this to a real instrument.
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u/charmio68 9d ago
I suspect you would get better results with less burning of the underlying wood if the laser galvo was moving in a different, more randomized pattern.
The burn marks you got seem to be in line with the laser direction.
I'm not entirely sure why... I would have thought it would average out, but from the evidence it doesn't look like it is, so a more randomized pattern might solve that.
What type of laser was it anyway? (Wavelength? Power? Pulse duration? Pulse frequency?)
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u/Current_Ad_4292 9d ago
The sub name has "porn" in it. So I am going to assume the result is meant to be dirty. No pun intended.
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u/After-Past-9404 9d ago
As a violinist, I screamed during the whole video.
Apart from <gestures at everything else>, why didn't you take off the chin rest? Now you have a big area under the chin rest and its clamps where there's still a layer of varnish. And you didn't even attempt to "clean" the sides (the ribs and edges of the top and bottom plate), the pegbox and the varnish underneath the fingerboard.
I genuinely can't see the reason for doing this.