Official Luthiers Forum!

WARNING ALERT *** Read last thread I posted!

In stead of hi-jacking David' Wren's excellent French polish video thread I thought it makes more sense to start a separate topic for spraying Royal Lac. I know Robbie O'Brien has a tutorial for brush application and there may be others spraying Royal Lac but this is my notes and schedule so YMMV:



1. Pore fill bare wood with West Systems epoxy. (I've used pumice based oil filler, shellac / pumice & acetone and two different brands of epoxy but settled on West as my filler of choice for now).
2. Let epoxy dry thoroughly for 48 hours.
3. Level sand epoxy with 320 grit leaving a thin film over the surface. If shiny pores or depressions are seen then apply another coat of epoxy. This may take more than one application depending on the pore sizes in the wood.
4. (Optional), seal everything with fresh flake shellac and allow to dry for 1 hour before top coating with Royal Lac.
5. Spray 4 coats of Royal-Lac per day at 3-4 hour intervals and let dry for 2 days.
6. Spray 4 coats again in a day and let it cure for 1 week.
7. Level (block) sand with 320 grit leaving a very thin film of Royal-Lac on the surface.
8. Spray 4 coats at 2 hour intervals and let dry for 10 days.
9. If you can put the RL finished guitar parts in a room or box with elevated temperature this will speed up the cure time. I put mine in a small room that is heated to 95*F.
10. After the finish has fully cured, level (wet) sand with 1000 grit by hand using a rubber block. I use an air powered RO sander using Klingspor part number FP73W, VD17344 sand paper. I mix 10 parts of water and 1 part of Murphy’s Oil Soap, as a wet sanding lubricant, in a spray bottle.
11. Be very careful sanding around edges or you may sand through, especially using a powered sander.
12. After sanding to an absolutely flat and satin finish (with no shiny spots visible), buff:
13. Power buff with Menzurna medium compound (Grizzly part number H0812)
14. Power buff with Menzurna polyester compound (Grizzly part number H0814)

* I buffed through my first Royal Lac guitar but I think I have the schedule worked out now that I have buffed more guitars successfully. The first guitar I sanded with 600 and 1000 dry, 1500 wet and finally 2000 wet then buffed with medium, fine and Polyester Menzurna dry buffing compounds. Obviously it was too much sanding and buffing as I buffed through the finish in several spots.

* Next I wet sanded another guitar with only 1000 grit, just until all the shiny spots were gone and the entire surface was satin (when wiped dry) then went straight to the buffer. I tried buffing with a few shiny spots left showing in the finish (low depressions in the orange peel) and the buffer would not take them out. I only buffed with two grades of compound, 1st with Menzurna medium and then a quick follow up with Menzurna polyester compound. The surface is brilliant, the highest gloss I have ever seen in any finish. The clarity is like none other. However, you MUST remove all low depressions before going to the buffer if you want a perfectly flat glass smooth surface.

* I've experienced shrinkage problems with RL sinking into softwood tops (Cedar, Engelmann, Sitka, Adi, Redwood, Carpathian, Italian and Lutz). I have sprayed over flake shellac seal coats and also over two different brands of epoxy and nothing made a discernible difference in the shrinkage. The only thing that resulted in the least shrinkage was to turn up the air pressure slightly, move the gun in a bit closer and move REALLY fast over the surface of the top. This produces a thinner and drier coat and I think this is the key to minimizing the shrinkage into soft wood tops.

*It would do me or you no good to discuss air pressure settings because my spray equipment would not be the same as yours so you will have to experiment to find the right spraying technique that works for you and your gun / fluid nozzle size, needle size and air cap size.

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tim...
http://www.mcknightguitars.com

Thank you, Tim. Great information.

I see some nice bursts on your website. Do you spray tinted RL, or are those other type finishes?

James

I've shot both James. Most of the bursts pictured on my sight are McFadden's cat urethane colors or nitro.

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tim...
http://www.mcknightguitars.com

Tim,

Thanks for the **Really** useful and thorough information.

I'm curious about the consistency of the RL product. I see that most of the people applying it are doing so with brush or pad, or with oil in a french polish procedure. Personally, I'm more interested in spraying than in wiping or brushing, although they have their benefits too. I always feel that I have more control over the level when spraying, and obviously it takes a lot less time and less coats than padding a finish on. Brushing always seems to leave me mystified over very uneven surface levels. A 2 lb cut of shellac seems to me to be pretty thin for spraying, so I'm wondering if the Royal Lac product comes in a thicker consistency for spraying, or is he working on something like that now?

How about drying time? Is there any need for additives to speed up the drying process, or does it dry fairly quickly like the padding procedure does?

How would you compare the gloss, warmth, and "natural" look of RL to a varnish like Epifanes? I really love the look of Epifanes, but it tends to build unevenly on light colored bindings, leaving them with a faint, almost tortoise-shell appearance which I find difficult to control.

I'm also curious about burn-in, and how difficult it may be to repair, as well as how tough it is in resisting body chemistry and scratches, etc. When I think shellac, I think " FRAGILE ! ".

Thanks!

P.S. I might be cool to get Vijay over here to participate in the conversation and chime in on his product. It seems almost "too good to be true", and yet some people I highly respect seem to love it.

-Don

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Oh, and while I'm at it... Does he have any other sizes than pints? I'm much more accustomed to buying at least quarts if not gallons of most finish products. I'd blow through a pint spraying in no time...

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

How much product is needed to spray 1 guitar. I am starting a mandolin project and was thinking french polish but my right shoulder would not like the motion so spraying will be a good alternative.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Hi Fred,
I ordered two gallons (in quarts) at a 26% ratio and I used a little over 1 gallon to spray 6 bodies and necks. My gun is an Iwatta HVLP which is very efficient and lets me shoot at low pressures with minimal over spray loss.When you order off the website you will get a more diluted ratio. VJ mixed up the 26% at my request. I have tested 33% and 50% ratios as well. The 33% and 50% were to viscous to spray out of the can through my gun and I had to cut them back with DA in order to spray them.

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tim...
http://www.mcknightguitars.com

Hi Tim

Could you tell me which West system product you use to pore fill? Thanks - Mike

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guitarsbygiltzow.com

Yes it does but VJ has to custom blend it per your request. He may be releasing a heavier bodied version specifically for spraying in the near future but more testing is needed?



I've tested several different solvent blend formulations from VJ and I think the best one for spraying so far is the lab grade alcohol he is currently using in the regular RL formulation. It tacks up quickly, similar to nitro so it holds on vertical surfaces [IF] you don't apply it too heavy.


It has a slight varnish-esque amber hue, but not overly amber like a straight short oil varnish like Epifanes or Rock Hard. Its much closer to Ace varnish or a cross between Ace and Nitro. Gloss isn't comparable to any other finish I have used to date. Epifanes has a high gloss but this product has an even higher gloss. Just look at the pictures of David' Wren's video. He captures the gloss very realistically with his camera and lighting. I recently photographed a Zircote body and it was THE most difficult to photograph guitar I have ever encountered. Its tough to take good images without seeing reflections, at least it was for me.

Clarity is another added bonus of RL. It has the best clarity of any finish I have tested as well.



It will burn in if you catch it within 2-3 weeks. After a month you will have to abrade it to get good adhesion. I've not seen any witness marks after repairs.

Its very abrasion resistant after a month. You can scratch it with your fingernails and it won't leave a mark. However, you can DENT the wood under the finish so this tells me the finish is flexible.

Adhesion is excellent. Michael Bashkin and I both did cross hatch adhesion tests and neither of us could get it to delaminate or flake off.






PSS, I should also mention that I have done some hot / cold testing as well. I have put both hardwood and softwoods finished samples (20 days old) in my deep freezer over night, pulled them out and brought them up to 95*F (VERY rapidly) and then back to the deep freezer and I had zero finish crazing or spider webbing. Its pretty amazing stuff!

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tim...
http://www.mcknightguitars.com

It'll be interesting to see how this stuff works out...

West 105 Resin + 207 clear hardener.

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tim...
http://www.mcknightguitars.com

Tim, I've placed an order with Vijay for a gallon, and will be trying it shortly.
Thanks for sharing all your test data and being so willing to educate the rest of us.
- It is greatly appreciated!

_________________
"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Iv,e always thought that French polish guitars always sounded better.Maybe just me. Does the Royal lac seem to have the same effect?

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James W Bolan
Nashville Tennessee

Hey Tim,

Of course, I should have asked the question before ordering but...

What are the vapors and off-gassing like with this product? I know that I can't spray nitro because of the solvents and off-gassing, so how about this stuff?

_________________
"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

James,
I have the same opinion as you of FP and yes I think it still holds true with RL.

Don,
Fumes are not unpleasant at all. I have similar issues with Nitro as well. Off gassing fumes make me sicker than a dog and I have yet to feel any of those effects with RL. I do wear a full respirator though when spraying.

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tim...
http://www.mcknightguitars.com

Thanks Tim.I`m gonna be tryin`some

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James W Bolan
Nashville Tennessee

thanks for the info Tim. Vijay told me you were doing some testing of the higher solids product. Glad to hear it worked out for you.

Does anybody know what the shelf-life is?

Tim, with your finish schedule, how thick do you think the final finish is? Thanks for sharing all this, btw. It's very interesting.

I believe it's 2 years.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

.002" - .003" at the bridge.

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tim...
http://www.mcknightguitars.com

I should have my gallon by next weekend, I hope. I will try to report back with my findings over the course of spraying and hopefully a positive outcome.

Thanks again Tim, for your help and advice.

_________________
"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Hi Tim:
Thanks for providing the great first hand information on this product. After following both Royal-Lac threads, I was persuaded to place my own order for the 26% material. I've been french polishing for a while and I'm really looking forward to giving the the sprayed Royal-Lac a go.

A couple of questions:

I might have missed it, but how long do you recommend letting the finish cure before final rub-out?

What's your best guess for the pound cut of the 26% Royal-lac?

Thanks,
Dean

Dean,

You can't push this stuff too fast if you plan to power buff it. Let it cure a full 30 days before buffing if time is on your side? I have buffed samples at 10, 20 and 30 day intervals and had some minor shrinkage (weeks later) at the 10 and 20 marks but none at 30. It behaves much like Nitro in this respect.

I am not sure of the cut at 26% but I am sure Vijay can answer that question. He is very helpful and generous with his time.

_________________
tim...
http://www.mcknightguitars.com

Please keep us posted of your progress Don and I'm glad I was able to help in some small way.

_________________
tim...
http://www.mcknightguitars.com

Hello to you all,
Please allow me to introduce myself.
My name is Vijay Velji, and owner of Shellacfinishes. Tim McKnight directed me to this thread.
First, hats off to Tim for his support and encouragement. He and I worked on many different formulations and with his relentless perseverance, we were able to come up with a formula that does amazingly well as his photos rightfully showcase!!
I was going through the posts and thought of inviting myself into it to hopefully shed some light on a few questions that were raised in the discussions. I am not a luthier and neither am I an expert in spray equipment. I have selected a few quotes from members as a way to address some technical points. They are as follows:
1) Don Williams:Oh, and while I'm at it... Does he have any other sizes than pints? I'm much more accustomed to buying at least quarts if not gallons of most finish products. I'd blow through a pint spraying in no time...
Answer: Yes, it is available. Please send me an email with your requirement. Shipping is always in quart size cans to avoid HazMat fees. Quart size cans are considered as Limited Quantity shipment.
2) Tim McKnight: I ordered two gallons (in quarts) at a 26% ratio and I used a little over 1 gallon to spray 6 bodies and necks. My gun is an Iwatta HVLP which is very efficient and lets me shoot at low pressures with minimal over spray loss.When you order off the website you will get a more diluted ratio. VJ mixed up the 26% at my request. I have tested 33% and 50% ratios as well. The 33% and 50% were to viscous to spray out of the can through my gun and I had to cut them back with DA in order to spray them.
Answer: A 26% solids by weight is available on special order. Royal-Lac is sold as a 2 lb cut solution. A 2 lb cut is ~20% solids. Tim is accustomed to spraying lacquers that range between 30-48% solids. In other words he lays down more solids per coat that he could with a 2lb cut Royal-Lac. As he mentions, going above 26% solids becomes difficult to spray since it is too viscous. Lacquers on the other hand, even though they contain more solids, are not as viscous as a 30% solids of Royal-Lac solution, because synthetic resins are designed for low molecular weight. Hence more solids in a less viscous solution. Since Royal-Lac contains mostly shellac whose molecular weight cannot be engineered, Tim's experiments prove that 26% is the best. This obviously means more coats. But all is not lost! I am working on a different formulation that may yield higher solids and at the same time give you the look and feel of shellac. So stay tuned.....
3) Tim McKnight: Adhesion is excellent. Michael Bashkin and I both did cross hatch adhesion tests and neither of us could get it to delaminate or flake off.
Answer: Adhesion of Royal-Lac will be by far better than any other finish. Adhesive qualities of thermoplastic resin are the best. Even though Royal-Lac is a thermoset polymer, it behaves like a thermoplastic polymer during the curing period. Over time it turns into a thermoplastic polymer as it nears cure. Lacquers on the other hand are and behave like thermoset polymers layer after layer since they are catalyst activated. That is why they are sand able in about 2-3 hours time. When layer after layer is applied, the layers adhere to each other but do not reactivate the previous layer to form a single layer.
4) James WB: Iv,e always thought that French polish guitars always sounded better.Maybe just me. Does the Royal lac seem to have the same effect?
Answer: Yes, Royal-Lac can be sprayed, padded, brushed and French Polished.
5) Don Williams: What are the vapors and off-gassing like with this product? I know that I can't spray nitro because of the solvents and off-gassing, so how about this stuff?
Answer: The vapors are caused by the 200 proof denatured alcohol that is used as the solvent in the system. The alcohol used has 90% ethanol, 5% Isopropanol and 2.5% methanol and 2.5% MIBK. Always good to wear a respirator and gloves. Highly recommended.
6) DeanP: What's your best guess for the pound cut of the 26% Royal-lac?
Answer: A 26% solids by weight will be about a tad bit less than a 3 lb cut. A 3 lb cut contains 27.2% solids.
7) Tim McKnight: You can't push this stuff too fast if you plan to power buff it. Let it cure a full 30 days before buffing if time is on your side? I have buffed samples at 10, 20 and 30 day intervals and had some minor shrinkage (weeks later) at the 10 and 20 marks but none at 30. It behaves much like Nitro in this respect.
Answer: That is correct. You can't push it too hard simply because Royal-Lac is not catalyst activated. It is dependent on curing by crosslinking with evaporation. Evaporation is related to temperature and humidity. Higher temperature and lower humidity means faster evaporation and hence faster curing. You would like the previous coat to be adequately dry before the next is applied, so that it slightly activates the first and so on. Tim has found a ways to atomize the coats in a way that allows him to lay down successive coats quite quickly. But in the end, you will have to let the finish cure by complete evaporation of the solvent.
If there are any other questions, please feel free to ask anytime. I hope I have covered some of the questions in detail. My apologies to those who suffer from short attention span! I know all of this can be quite boring!!