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a question for Laurent
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Author:  brenbrenCT [ Thu Jul 28, 2011 7:22 am ]
Post subject:  a question for Laurent
I was looking over your site the other day and saw you do oil varnish finish.

Can you briefly describe your process and materials? I'm currently testing sprayed shellac, hand rubbed and while i like it, it ends up being a bit delicate for the types of players buying my guitars.

Thanks in advance.

b
Author:  Tom West [ Thu Jul 28, 2011 10:57 am ]
Post subject:  Re: a question for Laurent
Brenden: Someone else who uses oil varnish is Bruce Sexauer. You may be able to catch him at the Unoffical Martin Guitar Forum.
Tom
Author:  Laurent Brondel [ Thu Jul 28, 2011 11:21 am ]
Post subject:  Re: a question for Laurent
B, there's nothing brief about the process, nor describing it. If you have specific questions I'll be glad to answer them to the best of my abilities.
Tom, did you get my reply to your request on oil varnish?
Bruce actually showed me the way, there are few differences between his and my method.
Author:  longdrive55 [ Thu Jul 28, 2011 11:55 am ]
Post subject:  Re: a question for Laurent
Hi Brendan,

Not to take anything away from Laurent, but in reference to Tom's suggestion about Bruce Sexauer I know he has a full write up on his process (with variations over the years) that he's been willing to share with other Luthiers.

As Tom suggested, contact him on UMGF or maybe AGF and ask if he'd be willing to share his write up.

Regards,

Erik
Author:  Tom West [ Thu Jul 28, 2011 2:56 pm ]
Post subject:  Re: a question for Laurent
Laurent: Yes ,I did get your reply. Thanks,much appreciated.
Tom
Author:  brenbrenCT [ Thu Jul 28, 2011 3:16 pm ]
Post subject:  Re: a question for Laurent
thanks guys.
Author:  alan stassforth [ Thu Jul 28, 2011 9:01 pm ]
Post subject:  Re: a question for Laurent
Woody's got a dvd for sale on oil varnish finishing.
Author:  James Orr [ Fri Jul 29, 2011 1:43 am ]
Post subject:  Re: a question for Laurent
And it's an excellent DVD!
Author:  CharlieT [ Fri Jul 29, 2011 2:02 am ]
Post subject:  Re: a question for Laurent
James Orr wrote:
And it's an excellent DVD!


[:Y:]
Author:  mqbernardo [ Fri Jul 29, 2011 6:34 am ]
Post subject:  Re: a question for Laurent
CharlieT wrote:
James Orr wrote:
And it's an excellent DVD!


[:Y:]

may i ask how can you get such DVD?

thanks,
miguel.
Author:  SteveSmith [ Fri Jul 29, 2011 9:54 am ]
Post subject:  Re: a question for Laurent
mqbernardo wrote:
CharlieT wrote:
James Orr wrote:
And it's an excellent DVD!


[:Y:]

may i ask how can you get such DVD?

thanks,
miguel.


http://brackettinstruments.com/store.html
Author:  mqbernardo [ Fri Jul 29, 2011 1:41 pm ]
Post subject:  Re: a question for Laurent
thanks!
Author:  Laurent Brondel [ Sat Jul 30, 2011 10:59 am ]
Post subject:  Re: a question for Laurent
Here's the "copy" of the varnish schedule I use, keep in mind that it perpetually evolves.
I no longer use Waterlox as a sealer, nor turpentine as a solvent. I also add about 20% acetone to the mix and keep adding as it evaporates. Neither do I wet sand (it's all dry sanding up to P1500). I scuff with the grey synthetic pads and 3M fine pads for the first 3 or 4 coats. Currently I use different varnishes, depending on what type of amber (or not) I desire. Epifanes clear varnish, Pratt & Lambert #38, Ace Interior Varnish & rarely Rockhard. They all have a different cure time.

As a sealer I use either Waterlox, a marine long oil varnish/sealer that is really penetrating. Or a spirit varnish (Behlen's violin varnish), or straight dewaxed blonde shellac, both considerably thinned. The choice of sealer depends on the B&S wood, I use spirit varnish (a shellac with added resin and gum) or shellac to block oily woods such as cocobolo since Waterlox, even with Japan drier added, may take forever to dry in those cases.
The sealer coat gets scuffed with 320grit or the maroon scotch brite pads.
Then goes the varnish, between 8 and 12 coats depending on the weather and how it goes. Each coat has to be scuffed (or slightly levelled if you get runs, dust and the like) before the next one goes on, as oil varnish will not stick well to oxidised (cured) varnish. Because of this I add about 5% acetone to the varnish, it seems to minimise witness lines, maximise adhesion and accelerate curing. When I get a good build, maybe around the 4th coat, I level with P600 wet. Then one more coat, levelled with P800, then (hopefully) the penultimate coat, levelled with P1000. I am very careful to spray the last coat as thick and level as I can, as the wet sanding starts (hopefully again) with P2000 and lastly P3000.
Then to the buffer with Menzerna fine and super-fine compound. Avoid at all cost to buff the corners and get a feel for it as varnish does not flow like lacquer. I move relatively slowly, 800rpm on the buffer, but am careful not to overheat the varnish. Absolutely no wax but some final and quick hand polishing with the Legend polish. My finish ends up in the vicinity of .004", all the time.

As soon as the can is opened the varnish thickens. It can be mixed with turpentine (real turpentine from pine pitch, not a substitute) if brushing, or naphtha if spraying, to regain the original consistency. A can of Bloxygen will really help to keep the varnish from turning into a skin in the can, as transferring the contents into smaller cans.
I did about 12 guitars with a brush, and then switched to a spray gun, life is too short…
If brushing you can add a couple of drops of kerosene to facilitate flow, start brushing from the middle toward the edges, not the opposite. I do middle to sides, then even things out with long strokes along the grain (always starting in the middle and lifting the brush as I reach the edge). That being said oil varnish cures slowly and if properly applied, tends to self level. The brush needs to be suspended in a turpentine solution between sessions, and care needs to be taken in not using more than 1/3 of the hair. Dust is the enemy, so is cold. The warmer your curing room, the faster the thing will cure. Usually I apply one coat per day, although sometimes 2 are possible (it takes 4/5 hours to dry). I buff after minimum one week, I prefer to wait 2 or 3 if possible.

I need to credit Bruce Sexauer for having given me many tips on his varnish process years ago.
Author:  woody b [ Sat Jul 30, 2011 1:11 pm ]
Post subject:  Re: a question for Laurent
I'll add, the slow curing of Varnish helps it flow out nice, but a dust free enviroment is really important. Nitro, and alot of other finishes are cured, or dried dust free in a matter, or seconds, up to minutes. Varnish takes at least an hour, sometimes longer to be dust free.
Author:  mqbernardo [ Sat Jul 30, 2011 1:59 pm ]
Post subject:  Re: a question for Laurent
wow, one of the reasons i like coming here so often... it´s rare the time when i don´t learn something new.

thanks a lot, guys!
miguel.
Author:  brenbrenCT [ Fri Aug 12, 2011 8:08 am ]
Post subject:  Re: a question for Laurent
an update:

after 2 weeks of thorough testing i have switched to sprayed varnish and i'm loving it. I find it pretty forgiving and i'm getting great results.

i'm prepping an instrument now for spraying so we'll see how it goes, but my samples came out great. it really pops the grain, even on spruce which is a nice plus.

thanks for everyone's help.

b
Author:  CharlieT [ Fri Aug 12, 2011 9:28 am ]
Post subject:  Re: a question for Laurent
brenbrenCT wrote:
an update:

after 2 weeks of thorough testing i have switched to sprayed varnish and i'm loving it. I find it pretty forgiving and i'm getting great results.

i'm prepping an instrument now for spraying so we'll see how it goes, but my samples came out great. it really pops the grain, even on spruce which is a nice plus.

thanks for everyone's help.

b


Glad to hear it, Brendan. I've been doing some testing with varnish as well. May I ask which varnish you are using?
Author:  brenbrenCT [ Fri Aug 12, 2011 12:17 pm ]
Post subject:  Re: a question for Laurent
CharlieT wrote:
brenbrenCT wrote:
an update:

after 2 weeks of thorough testing i have switched to sprayed varnish and i'm loving it. I find it pretty forgiving and i'm getting great results.

i'm prepping an instrument now for spraying so we'll see how it goes, but my samples came out great. it really pops the grain, even on spruce which is a nice plus.

thanks for everyone's help.

b


Glad to hear it, Brendan. I've been doing some testing with varnish as well. May I ask which varnish you are using?


i tested Watco's danish oil, Woodcrafts 100% Tung Oil (not varnish), minwax's Helsman, and Formsby's Low Gloss Tung Oil.

I like Formsby's the best so far. It sprays very consistently, and seems to dry in about 4-5 hours. I let it sit in my gun too long for one test, and it's taking forever to dry. So i would recommend using as little as possible, and make sure to test what's in the can frequently to see if it needs thinning.

I buy it in 8oz cans to limit the problem of it drying out in the can.
Author:  DarrenFiggs [ Fri Sep 30, 2011 12:24 pm ]
Post subject:  Re: a question for Laurent
Laurent, are you dry sanding up to P1500 with an ROS? What brand of abrasive do you use?
Author:  Laurent Brondel [ Fri Sep 30, 2011 1:24 pm ]
Post subject:  Re: a question for Laurent
For dry sanding finishes I use Klingspor stearate sandpaper, P600 to P1500.
Author:  DarrenFiggs [ Fri Sep 30, 2011 1:58 pm ]
Post subject:  Re: a question for Laurent
Thanks, Laurent. I noticed your post about General Finishes, are you moving away from varnish?
Author:  Laurent Brondel [ Fri Sep 30, 2011 3:30 pm ]
Post subject:  Re: a question for Laurent
DarrenFiggs wrote:
…are you moving away from varnish?
No, I consider oil varnish an integral part of my building philosophy. However I occasionally need a tougher finish.
Author:  woody b [ Sat Oct 01, 2011 7:33 am ]
Post subject:  Re: a question for Laurent
Laurent Brondel wrote:
DarrenFiggs wrote:
…are you moving away from varnish?
No, I consider oil varnish an integral part of my building philosophy. However I occasionally need a tougher finish.



Since you're a professional with extensive knowledge of needed safety requirements I'd recommend polyester when you need a tougher finish. I've used polyester on my necks for quite a while. I think conversion varnish might be another option( it is tougher than oil varnish isn't it?) . I've never used conversion varnish though.
Author:  Laurent Brondel [ Sun Oct 02, 2011 7:58 am ]
Post subject:  Re: a question for Laurent
Woody, poly and urethane finishes are out of my realm, as much as nitro lacquer is. I do not have the level of spray & safety equipment required to deal with the toxicity and VOC, and even if I did I would still value my health (and the environment around me) much more than my guitars. What intrigues me is the possibility of a tough finish with very low toxicity and VOC.
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