Finishing question for Kiwigeo

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sebastiaan56
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Finishing question for Kiwigeo

Post by sebastiaan56 » Wed Oct 31, 2007 6:15 am

Ive started finishing this kit from Mal Ohlsen. In other places you have stated you use Z-Poxy as the filler. So I bought me some (8 hr turnaround from Barnes OnLine!!). Did one coat on the back last night, looks very good.

The question do you fill the soundboard? The one I am making is Western Red Cedar. Also, do you dilute with metho for the neck?

Thanks

Sebastiaan

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Bob Connor
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Post by Bob Connor » Wed Oct 31, 2007 7:32 am

Hi Sebastiaan

Z-poxy or other fillers aren't used or needed on soundboards because there aren't any pores to fill.

I have heard of one wood vendor who suggested to use it on a curly Redwood top to pop the grain.

I've just done a blackwood guitar with z-poxy.

The method I use is one coat - then sand back to bare wood. Apply a second coat and also sand back to bare wood.

Another way is to apply the epoxy , then level sand it.

I don't thin it down at all and use it on the neck full strength.

Cheers

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Arnt
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Post by Arnt » Wed Oct 31, 2007 7:40 am

Hi Sebastiaan,
obviously I'm not Kiwigeo, but I have used Z-poxy as a filler on several instruments. I only use it to fill the pores on open pored woods like rosewood and mahogany, and I sand back to bare wood to make sure the epoxy is only in the pores before I continue with the finishing. Non porous woods like cedar or spruce really don't have any pores that need filling to achieve a nice level finish surface so it is not needed on those wood for that purpose.

Yet some builders like to use a thin layer of the epoxy on the the soundboard as a ground coat before the clear finish coats go on, I believe mostly to get that slight amber hue it gives to the finish. It may also help with finish adhesion, in situations where this is a problem.
Arnt Rian,
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Arnt
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Post by Arnt » Wed Oct 31, 2007 7:44 am

There I go, typing too slowly again... Glad to see Bob agrees with me, though!

About thinning; no I don't thin it at all, it it pretty thin as it is. I have used regular hardware store epoxies (as in glues) as fillers before, and they needed thinning. They also gummed up sand papers like crazy and were a pain to use compared to Z-poxy.
Arnt Rian,
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kiwigeo
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Post by kiwigeo » Wed Oct 31, 2007 8:08 am

Bob and Arnt have answered your questions. On a sound board I wouldnt use zpoxy except if I was desperate to add colour to the wood. I dont like a rigid finish on a piece of wood I want to be free to vibrate.

For diluting zpoxy I use the same technical grade (100%) meths I use for my french polishing.

Cheers Martin

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sebastiaan56
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Post by sebastiaan56 » Wed Oct 31, 2007 8:24 am

Thanks everyone,

All obvious enough when I read your replys but not when I asked the question. On the neck do you apply with a lint free cloth or brush?

Martin, Denatured alcohol for what reason, stops cloudiness?

BTW Arnt, I want to pick your brains on how you bound that F5. Did you make templates to bend the binding on? Did you route the channels or cut by hand? It looks like you have done a fine, fine job

Sebastiaan

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Post by Hesh1956 » Wed Oct 31, 2007 8:42 am

Hi Sebastiaan:

I just wanted to weigh in here too.

First we probably should say "epoxy finishing resin" and not just epoxy because they are not the same thing. Z-Poxy, System III, and West Systems can be used as finishing resins. Z-Poxy also makes regular epoxy that is not suitable for use as a pore filler. As stated above, or below, :D epoxy finishing resin is thinner and sands much better.

I usually do two coats on the entire guitar except the top and then level sand. Typically when level sanding you will sand through in spots. You will see that the epoxy finishing resin pops wood figure like nothing else and darkens it a tad too. Epoxy breaks down with UV exposure and develops a slight amber tint that I find very pleasing. Kind of an aged look like me..... :D

System III is more clear over time then Z-Poxy is.

Anyway after level sanding I mix the EFR (that's easier to type) 50 : 50 with either denatured alcohol of grain alcohol. The grain alcohol contains nothing toxic so that is my preference and you can drink the stuff if you get bored...... :dri

I take the mixture and just wipe it on the entire guitar with a lint free cloth to even out the color where I have sanded through. This includes the top although the other guys are correct no pore filling is required here. But you may have say an Engleman Spruce or Carpathian Spruce top that is as white as Britney Spear's teeth and that would look funny on a guitar. Wiping this mixture on the guitar only leaves a very thin film that is nothing like the full strength EFR that you used on the back and sides. It is simply to add a bit of an amber tint to the top that some find pleasing.

I hope this helps.

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kiwigeo
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Post by kiwigeo » Wed Oct 31, 2007 9:09 am

sebastiaan56 wrote:
Martin, Denatured alcohol for what reason, stops cloudiness?
I must admit I only use the technical grade meths because theres always a bottle of the stuff sitting on my bench.

I imagine having any water in the mix wouldnt be a good thing. Maybe someone could mix up some domestic grade meths with z-poxy and see if it does go cloudy. Might to it myself one day and report back.

Cheers Martin

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sebastiaan56
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Post by sebastiaan56 » Wed Oct 31, 2007 9:36 am

Hesh1956 wrote:The grain alcohol contains nothing toxic so that is my preference and you can drink the stuff if you get bored...... :
Hi Hesh,

and your Uncle Ebner runs a still out the back?!? verry nice, verry cheap?!? Still kits can be bought here and Ive often wondered. Ive heard that raw alcohol is one of two things that cause blindness and Im not sure I should risk both... :wink: Yeh.... Lutherie and raw alcohol....

Seriously, thanks for the input mate. The top is WRC so it is already fairly dark, but hey, gothic is in! and it will have a rough life, the people who I am building it for arent the most careful. so I may do a number coats of the Hard Shellac instead. I agree with your comments on making figure pop!

I might try both alcohols as well Martin but I dont have much experience yet. Meths is certainly cheaper,

Once agan, thanks,

Sebastiaan

Hesh1956
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Going Blind

Post by Hesh1956 » Wed Oct 31, 2007 12:04 pm

sebastiaan56 wrote:
and your Uncle Ebner runs a still out the back?!? verry nice, verry cheap?!? Still kits can be bought here and Ive often wondered. Ive heard that raw alcohol is one of two things that cause blindness and Im not sure I should risk both... :wink: Yeh.... Lutherie and raw alcohol....



Sebastiaan
Sebastiaan how did you know that I have an Uncle Ebner :D Actually you can purchase 190 proof grain alcohol in some states in the US. My state was not one of them so I had it smuggled in by another member here JJ.

Great recovery on the "going blind" comment you have me rolling on the floor laughing. :cl :cl :cl

I have to go now because the woman that reads posts to me out loud and types my responses, since I have been blind since my teen years, wants to watch the TV.... :D

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Bob Connor
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Post by Bob Connor » Wed Oct 31, 2007 12:06 pm

Sebastiaan

We only use 100% metho for anything we do. The only place I can find it is from Haymes paint shops.

Bob

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sebastiaan56
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Post by sebastiaan56 » Wed Oct 31, 2007 12:43 pm

bob wrote:Sebastiaan

We only use 100% metho for anything we do. The only place I can find it is from Haymes paint shops.

Bob
Hi Bob

My local Haynes didnt have any, I went to an auto finisher supplies shop. Tried to sell me nitro, I got the best look when I mentioned French Polish.... but he sold me a litre anyway. They also had 1500 and 2000 wet and dry, useful place. Car guys share concerns about finishing, point taken on 100% ethanol, thx

Hi Hesh, I had to sack my seeing eye dog, it kept drinking my supplies.

Sebastiaan

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Arnt
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Post by Arnt » Wed Oct 31, 2007 7:01 pm

For what its worth, I only use denatured alcohol ("Red Spirit" up here) to thin epoxy and I have not had any problems with it. I also use it to dissolve shellac, it works fine for that too. I should probably try something more pure, it is not like it is very difficult to fine an "uncle Ebner" in this part of Norway...

About the F5 binding; the bindings are ivoroid (sp?) plastic, and can be bent by hand for most of the curves. For the tightest bends they need to be warmed a bit, I just use a heat gun. Go easy with the heat, this material will distort a bit and then ignite if it gets too hot! Most of the binding rabbet I cut on the router table with a binding cutter from Stewmac protruding through a "donut" spacer, and small spool clamps to keep the instrument level. The difficult scroll parts are cut by hand. The binding of an F5 is pretty demanding work and takes a lot of patience and practice to do well. There are some pretty good pictorials of the process on the web; have looked a lot at this one of a true master of the craft, Lynn Dudenbostel.

http://www.thefishnet.com/makemandolin/newmake.htm

For future reference it would probably be a good idea to start a new thread when you introduce a new topic. We need more mandolin threads here anyways!
Arnt Rian,
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kiwigeo
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Post by kiwigeo » Wed Oct 31, 2007 10:50 pm

My technical grade meths comes from a furniture restoration supply house here in Adelaide. They get it from a supplier called "Polytreat" also here in Adelaide.

Check out a few furniture restoration businesses and see where they get their tech grade meths.

Cheers Martin

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Post by kiwigeo » Wed Oct 31, 2007 10:55 pm

Sebastiaan,

Try Complete Hardware at Eastwood, apparently they have it in their paint section. Ask for IMS grade 100% meths.

Cheers Martin

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