How to UV Finish

Talk about musical instrument construction, setup and repair.

Moderators: kiwigeo, Jeremy D

Post Reply
simso
Blackwood
Posts: 1604
Joined: Mon Apr 25, 2011 10:36 pm
Location: Perth WA

How to UV Finish

Post by simso » Fri May 04, 2018 4:20 pm

Probably of interest to every builder, the way of the future this stuff.

http://www.mirwa.com.au/HTS_Uv_Paint.html
Attachments
HTS Uv Finishing.JPG
HTS Uv Finishing.JPG (145.27 KiB) Viewed 1249 times
Steve
Master of nothing,

Do your own repairs - http://www.mirwa.com.au/How_to_Series.html

User avatar
kiwigeo
Admin
Posts: 9388
Joined: Sat Sep 29, 2007 5:57 pm
Location: Adelaide, Sth Australia

Re: How to UV Finish

Post by kiwigeo » Fri May 04, 2018 4:29 pm

Thanks Steve.......

A question - what was approximate cost of the curing equipment?
Martin

simso
Blackwood
Posts: 1604
Joined: Mon Apr 25, 2011 10:36 pm
Location: Perth WA

Re: How to UV Finish

Post by simso » Fri May 04, 2018 4:49 pm

Still in the ridiculous price range but slowly coming down, I think the hand held units are about 3500usd, the full booths which I think Perry has gone for or is doing is around 15000 or so, pretty neat setups.

From raw wood to finished buffed painted into a shipping box at the end of the day

With the hand held units you have to be a bit more aware of hand speeds, if you are curing rosewood you can boil the oils in the wood and they burst through the finish, it gets that hot, but in a booth its constantly moving and rotating so super neat.

Steve
Steve
Master of nothing,

Do your own repairs - http://www.mirwa.com.au/How_to_Series.html

User avatar
kiwigeo
Admin
Posts: 9388
Joined: Sat Sep 29, 2007 5:57 pm
Location: Adelaide, Sth Australia

Re: How to UV Finish

Post by kiwigeo » Fri May 04, 2018 5:07 pm

Thanks Steve.....out of my price range. Think I'll stick with the French Polishing :mrgreen:
Martin

blackalex1952
Blackwood
Posts: 540
Joined: Tue Aug 27, 2013 6:36 pm
Location: North East Victoria

Re: How to UV Finish

Post by blackalex1952 » Fri May 04, 2018 5:44 pm

Thanks Steve.....out of my price range. Think I'll stick with the French Polishing :mrgreen:
Shellac is non toxic and doesn't support the oil, plastic and chemical industries. Its also a much finer lighter finish for soundboards, as we all know and easily repaired to boot. -Ross
"Everything I say on the topic is based solely upon inexperience and assumption!"

simso
Blackwood
Posts: 1604
Joined: Mon Apr 25, 2011 10:36 pm
Location: Perth WA

Re: How to UV Finish

Post by simso » Fri May 04, 2018 6:12 pm

Totally agree, but like everything the more it gets used the cheaper the product becomes.

With PRS and Maton I believe now using it, as well as Taylor and a few other builders, the costs go down.

One day I can see a full setup costing less than a 1000 dollars, which is worth every cent.

The other thing becuase you need to sand each layer for the next layer to grip you end up with super thin finish, taylor I think advertise theirs as less than 5 thou.

Anyways, interesting for those who wondered how it was done :D

Steve
Steve
Master of nothing,

Do your own repairs - http://www.mirwa.com.au/How_to_Series.html

User avatar
Allen
Blackwood
Posts: 5053
Joined: Thu Oct 11, 2007 5:39 pm
Location: Cairns, Australia
Contact:

Re: How to UV Finish

Post by Allen » Sat May 05, 2018 7:01 am

I did a lot of enquires about the UV curing, and the advice was to stay away from it unless you are into big time production.

Even then there are issues that come up with adhesion to some timber, and curing where you have to go with a combination of catalyst and UV cure. Some of the guys I asked had some nightmares of stock coming back with gummy uncured finish showing up months down the track.

Since then I've swithced to a catalysed polyurethane and from start of pore fill to full buff out it's 4-5 days. Polyurethane doesn't have the adhesion problems to rosewoods and unlike lacquer no clogging of sandpaper. No gasing off for weeks. No spray sessions lasting for hours. No shrink back a month later.

And my finish ends up being 1/2 the thickness of what I had using lacquer.
Allen R. McFarlen
https://www.brguitars.com
Facebook
Cairns, Australia

simso
Blackwood
Posts: 1604
Joined: Mon Apr 25, 2011 10:36 pm
Location: Perth WA

Re: How to UV Finish

Post by simso » Sat May 05, 2018 10:36 am

I like poly as well.

Uv is very process orientated, you need to coarse sand it, you need to cure it properly, if I was going into production I would get a cabinet not a hand held unit, then you know it’s fully cured

Steve
Steve
Master of nothing,

Do your own repairs - http://www.mirwa.com.au/How_to_Series.html

blackalex1952
Blackwood
Posts: 540
Joined: Tue Aug 27, 2013 6:36 pm
Location: North East Victoria

Re: How to UV Finish

Post by blackalex1952 » Sat May 05, 2018 5:28 pm

And my finish ends up being 1/2 the thickness of what I had using lacquer.
So does this imply that it is in fact a thinner lighter finish than shellac and nitrocellulose? Also how about finish repairs eg drop filling and levelling, also colour matching with both dyes and pigments? How does it react with other finishes underneath?

Ross
"Everything I say on the topic is based solely upon inexperience and assumption!"

simso
Blackwood
Posts: 1604
Joined: Mon Apr 25, 2011 10:36 pm
Location: Perth WA

Re: How to UV Finish

Post by simso » Sat May 05, 2018 10:15 pm

I can genuinely say as a person that loves nitro and for example, I love nitro so much that I even use it to do repairs on Taylor’s as well, uv finished surfaces are very thin as each layer requires mechanical keying as you may have noticed in my walk through.

It’s only good for clear finishes, you can get sealer that is coloured, like brown, and so forth, so as per tutorial you sealer coat in brown stained uv and then follow up with clear coats

As far as I know, you cannot stain clear coats, that prevents the uv light from getting in. I could be wrong here.

It’s no good for using over other finishes, it’s a raw wood to final finish product.

The advantages of uv are application time and durability.

For repairs, you really can’t go wrong, remember the taylor super glue drip fill repair I did, here’s a reminder link, it comes up pretty good.

Don’t think I’m trying to sell a product here, I am merely showing the advantages to uv, if I was a small manufacturer, and small being 5-10 guitars a month, I would not hesitate to go a full uv Setup for my product.

http://www.mirwa.com.au/HTS_Superglue_Drip_Fill.html

Steve
Steve
Master of nothing,

Do your own repairs - http://www.mirwa.com.au/How_to_Series.html

User avatar
Allen
Blackwood
Posts: 5053
Joined: Thu Oct 11, 2007 5:39 pm
Location: Cairns, Australia
Contact:

Re: How to UV Finish

Post by Allen » Sun May 06, 2018 7:02 am

Polyurethane that I use certainly is thinner, and way more durable than lacquer. Not thinner than French Polish, but again way more durable. Application and technique is everything, and really not for a beginner.

Repairing it would be no different than doing spot repairs on automobiles. And that was my proffesion for 37 years.

I never add color to my finishes, but I do know many that do, and it's certainly a standard practice with some of the flash color finishes in the automotive industry.

Drop filling with either CA or the product itself is way easier than in laquer.
Allen R. McFarlen
https://www.brguitars.com
Facebook
Cairns, Australia

User avatar
J.F. Custom
Blackwood
Posts: 762
Joined: Fri May 01, 2009 9:13 pm
Location: Victoria
Contact:

Re: How to UV Finish

Post by J.F. Custom » Mon May 07, 2018 10:43 pm

Allen wrote:
Sat May 05, 2018 7:01 am
...Since then I've swithced to a catalysed polyurethane ...
Hey Allen.

Curious as to what brand/product you are referring to here? What pore fill method are you combining with this one and how long have you been using/testing it? Does it apply much like the pre-cat lacquer? Same multi coat approach? Sorry for all the questions! Just interesting as I've not come across a pre-cat poly before. What made you change?

With respect to the UV finishing, I am hesitant to invest in yet more technology just to finish an instrument. I can see the value for production environments in the time saving, but personally could not justify it over all the options at my disposal now. These already vary in application time, equipment required and finish desired - plenty of choice and I'm not in that much of a rush. I'm currently looking at the other end of the spectrum in terms of low tech, little complexity of application and sheer dollar investment; some new non-toxic drying oils. Not sure of their suitability yet but we'll see.

On the other hand, has anyone seen the UV cure repair kits? They look like a white out style pen, but are full of a UV sensitive clear resin and have a built in little UV LED. Put a drop on a surface and UV 'cook' it with the mini spotlight for 30 secs - hard and clear as glass. Interesting for repair work or other small jobs I think...

Cheers,

Jeremy.

User avatar
Allen
Blackwood
Posts: 5053
Joined: Thu Oct 11, 2007 5:39 pm
Location: Cairns, Australia
Contact:

Re: How to UV Finish

Post by Allen » Tue May 08, 2018 7:02 am

I use Bote Cote epoxy. 2 sessions does most timber, but sometimes 3.

The Polyurethane is Mirothane by Mirotone. So anyone in Australia or New Zealand will be able to get it.

I build 4-6 instruments every month and I switched because for me the finishing process is the bottle neck in my business. I managed to take 6 weeks out of the build time with much superior results over lacquer.

It's a 2K system with a selection of catalysts that will determine the level of gloss off the gun. But if you sand and buff they are going to end up gloss anyway. I'm using their high performance system. Same catalyst for both the sealer and clear.

I use the ultra slow solvent. I don't know what the faster solvents would be like. But in the mid 20's to mid 30's C this stuff is still plenty fast. Dust free in the 5 minutes but alows you to apply in a very thin flowing coat.

Their sanding sealer is a 2:1 +25% thinner mix. A couple of coats with a 5 minute flash off between. 2 hours later it's ready to sand.

The clear is a 1:1 + 25% thinner mix. 3-4 thin flowing coats with a 5 minute flash off. I let cure overnight. Level sand and the same the next day. Day after onto level sand and buff.

As long as you're competent with the spray gun, you shouldn't have any problems.
Allen R. McFarlen
https://www.brguitars.com
Facebook
Cairns, Australia

User avatar
J.F. Custom
Blackwood
Posts: 762
Joined: Fri May 01, 2009 9:13 pm
Location: Victoria
Contact:

Re: How to UV Finish

Post by J.F. Custom » Fri May 11, 2018 8:36 pm

Thanks Allen.

That's great info and I appreciate you taking the time to answer.

May give it a go some time down the track.

Cheers,

Jeremy.

Post Reply

Who is online

Users browsing this forum: Google and 15 guests