New Luthier Tips du Jour video - UV finish systems

[Robbie O'Brien]

Here is the latest Luthier Tips du Jour video -The topic is UV finish curing systems
This video as well as all my other videos are available via my website, LMI's website or on Youtube.
Enjoy!


youtu.be/

[Ormsby Guitars]

I cannot express how excited I am to move over to a full UV system in the very near future. So sick and tired of the current system.

[Allen]

Have you found a source for the finishes in Australia Perry?

[Ormsby Guitars]

I dont believe there is one. Imports all the way!

[demonx]

The whole handheld thing seems like a big pain in the butt though - I understand it drops the price substantially from the cabinets or stand setups - but...

[simso]

Using the hand held unit is really inconsiquential. Its like spraying another coat of lacquer.

In Perrys situation, as its more for building in volume rather than repairing I would go the full automated cabinet.

Yes the only suppliers at the momment for consumables is overseas, costs me more in shipping than it does for the product as its shipped hazadarous.

[DarwinStrings]

This sort of finish certainly has my interest. Any negatives? other than price and availability. Robbie said there that you can get it on thin. Its tough and fast, I also assume you get a mirror gloss, does it look as good as lacquer? From having a bit of a read it looks like you could DIY a lamp fairly cheap like a metal halide (mercury is one that is used) but you also have to have the product matched to the lamp and some of the finishes need more expensive lamps. The stuff is green, so they say and no VOC, water clean up. I guess like most stuff nothing is perfect but this gear is looking a bit like the future.

Jim

[Robbie O'Brien]

This sort of finish certainly has my interest. Any negatives? other than price and availability. Robbie said there that you can get it on thin. Its tough and fast, I also assume you get a mirror gloss, does it look as good as lacquer? From having a bit of a read it looks like you could DIY a lamp fairly cheap like a metal halide (mercury is one that is used) but you also have to have the product matched to the lamp and some of the finishes need more expensive lamps. The stuff is green, so they say and no VOC, water clean up. I guess like most stuff nothing is perfect but this gear is looking a bit like the future.

Jim

Jim,

All finishes have pros and cons. Uv certainly has some cons. It builds in layers, smells bad, must use an adhesion promoter, needs a UV lamp to cure etc. It is true that it has lower voc levels than lacquer but I don't know if I would call it green and it certainly is not water clean up.
I consider UV curable finishes just another option in my finishing arsenal.

[DarwinStrings]

Thanks Robbie, This quote from a company that produces the lamps, "Combining exceptional durability, cost effective process; UV curing is an attractive option for quality wood finishers. As a "green" technology, ultraviolet overcomes the limitations of solvent-based, thermally-cured coating producing a premium finish while in compliance with VOC environment mandates. Containing no organic solvents, there are no harmful emissions. Equipment can be cleaned with water." was where I got that from so I guess either they are wrong or there are a few different types.

Jim

[Ormsby Guitars]

PRS have moved over to full UV since late last year. Try and fault their finishes for gloss and clarity.

[Allen]

Jim, living in the tropics, all we would have to do is walk outside with it for a minute or so.

Another option is just to use MEK for the catalyst instead of UV. Not as fast, but not as expensive to set up for the polyester finish either. It's what Rick Turner does. At least the last time I heard him mention it a few weeks back.

[simso]

Maton switched over last year to uv, Id say with cole clark getting sold off, that they will go uv as well as the new ceo is about cutting costs down.

The finish is like glass, it truly is mind blowing, but same as applying any product hand skill is involved in the application of the spray, however drying time ceases to exist.

You cannot clean up with water or thin down, basically its sold as a sprayable product, we leave one of our guns full with uv clear in it, we dont clean the gun / empty the gun for months at a time, so long as the liquid is protected from uv light it will stay liquid.

The curing on the other hand is dangerous and can be destructive.

When you spray, you then cure with a hand held unit, but not always does the uv cure, sometimes you have to move slower sometimes faster, there is no hard and fast rule, except that it should not be tacky to the touch after curing. So we cure a guitar and then run bare hand over it, those araes tacky need more exposure.

There are some downsides

1st - cost, but this IMO will come down with more acceptance in the guitar world
2nd - If you move the lamp to slow it can and will burn the guitar, the heat is very intense, if you hold it above a rosewood back in one spot for about 10 seconds the oils in the rosewood will bubble and pop through the finish, ask me how I know.........
3rd - Ive found some reactions occur between glue Ive used to hold binding on and then the uv application afterwards when curing. Ive also found some plastics go brittle and break of the guitars after being exposed to the high intenisty UV.

Theres lots of pros and cons, but the best is time saving.

Steve


But there are some hazards.

[simso]

Forgot one

4th - If you put it on to thick, the lower layers wont cure, it needs high intensity light to cure it, so any deep layers dont ever cure. The strength of the light can only penetrate so deep

Weve also had issues with stains and colourings stopping penetration of the UV light

Taylor switched over to another UV in the last year or so because of this exact reason, talking with them, they now have a UV curable product, that also continues to cure with time, so this alleviates those lower layers not curing coming back and causing an issue>

Anything to do with UV, I would ask Rob at Taylor first, IMO they led the field into UV and are the pioneers and are always on the forefront of improving there product.

Theres lots of pros and cons, but the best is time saving, I for one am happy with the progression to UV and would not turn back, but like everything there is a learning curve

Steve

[Ormsby Guitars]

Moving to UV, will save me 420 hours, just based on current orders. will pay for itself instantly I reckon. Just waiting for a break in production to switch over!

[Robbie O'Brien]

Thanks Robbie, This quote from a company that produces the lamps, "Combining exceptional durability, cost effective process; UV curing is an attractive option for quality wood finishers. As a "green" technology, ultraviolet overcomes the limitations of solvent-based, thermally-cured coating producing a premium finish while in compliance with VOC environment mandates. Containing no organic solvents, there are no harmful emissions. Equipment can be cleaned with water." was where I got that from so I guess either they are wrong or there are a few different types.

Jim

I have used a water based UV curable adhesion promoter before but was not aware of anyone making a water based UV curable topcoat. I will have to look into that.
UV finishes do have a learning curve so if you are considering delving into the world of UV curable finishes they require a bit of trial and error just like learning any other type of finish.
Good luck and Happy Finishing from O'Brien Guitars.

[Allen]

Rick Turner told me that some woods act like an anti-catalyst too. With finishes turning soft and gummy down the track. A very expensive learning curve should it bite you on the bum.

[DarwinStrings]

Now there is a spanner in the works Allen, perhaps we will need to continue playing them out in the sun up north.

One of the funny things about all this to me is that I prefer the low sheen look but I continue the high gloss look cause that is what it seems most people prefer. Trevor has a PNG RW guitar that he just shellacked without even a pore fill and it looked great to me as does the furniture I make without a grain fill and a drying oil finish.

"Gummy", I don't reckon you'd be happy pulling your guitar out of the case covered in coloured fur

Jim

[Trevor Gore]

The big down side for me is that the finish is polyester. I don't know a finish that has more damping and it is very audible on acoustics. Whilst I haven't tried UV cured polyester, I've used a couple of other chemical catalyst types, just for grain filling, just on backs and sides and I can hear it immediately (compared to no fill or an epoxy fill). The polyester I've tried as a filler also sinks back under nitro over time. So if you want a fill, you have to put it on thick, and probably use a full polyester schedule.

I understand that there are also UV cure polyurethanes, which might be better on the damping front. Whilst PU is a great material, and very versatile in all sorts of applications, it's very toxic, too, so would need a lot of kit to keep you safe.

BTW, NGR, no pore fill, hard shellac finish, is a great way to go. Both Jim and I think it looks great. Just a shame everyone seems to want high gloss on expensive guitars.