Homemade Pine varnish

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Ian Taylor
Posts: 4
Joined: Sat Oct 13, 2018 5:26 pm

Homemade Pine varnish

Post by Ian Taylor »

Hi, first post here.

I've made my own varnish by collecting chunks of sap from Norfolk pine trees, soaking it in turpentine in the sun for a week or more, then boiling it with some linseed oil and straining it through cheesecloth. I was amazed at the look, the golden color is stunning and more important I think there is some sort of magical quality that it makes happen with the wood's sound.

The problem is, and I'm sure everyone knows this, that my homemade varnish is more like "no" drying than "slow" drying. It's still a bit sticky after a year! As result, it gets dirty and has all the problems that made everyone go to plastic that to me sounds terrible.

Q1: Has anybody figured out a way around the drying time? I've used Japan dryer and it made no difference, except add an odd stain.

Q2: there's these plums here (Hawaii) that drop on people's cars and make a bad purple stain. A friend of mine tried to make some wine with them and it tasted terrible. I mashed some up and stained a guitar amp I reboxed with the juice followed by a topcoat of my homemade varnish. Until it faded (about 2 weeks) I thought I'd been visited by Elvis, it looked so incredible. Until it faded. Does anybody know how to stop that fading other than with something like a UV varnish?
Alan Carruth
Posts: 1265
Joined: Sun Jan 15, 2012 1:11 pm

Re: Homemade Pine varnish

Post by Alan Carruth »

I made some terpene resin varnish once that didn't dry well. I didn't cook it enough. If my experience there is any guide (and don't take this as gospel) you need to go about it a bit differently.

The directions I got for making the varnish said to cook the resin and oil together without any turps at a fairly high temperature (350F?) until they form a co-polymer. The way you tell is to put a drop of the mix onto a plate of glass to cool a bit, and touch it with your finger. You should be able to draw it out into a thread about three feet long. Once it reaches that stage you can cool it below the boiling point of the turps and add that. I didn't cook mine long enough. With the thinner in it you may not have been able to get a high enough temperature.

You do this outdoors on an electric hot plate. Make a small amount in a deep pan in case it wants to foam up. It will smoke.

The directions I got specified the use of raw, cold pressed linseed oil. 'Boiled' linseed oil has metallic driers in it that are catalysts, and they might mess things up. Hot pressed oil will have proteins in it that will weaken the film. I got mine at a health food store as salad oil; hot pressed oil is said to be indigestible.

In his 'Artists Handbook' Meyers says that it's impossible to make oil-resin varnish in batches of less then 200 gallons with sufficient quality control. The final product depends on not only the oil and resin used, and the proportions, but also on how hot you get it, how long it takes to heat up and cool down, and how long you hold it at the high temperature. The Hill book on Strad mentions the variability of the varnish frequently.

Speaking of resins: rosin is abietic acid. It is said to make a very beautiful varnish the crazes badly after a while because of the acidity. I don't know if your resin is like that. Some folks neutralize it with a potassium soap. Sodium hydroxide may be bad news.

I will try to find the article with more details in the old Gatgut Society 'Newsletter'.
Ian Taylor
Posts: 4
Joined: Sat Oct 13, 2018 5:26 pm

Re: Homemade Pine varnish

Post by Ian Taylor »

Thanks Alan for your help. It would take a pretty good size operation to make 200 gallon batches!

I've been researching this and collecting as much info as I can in a file. The varnish I did 8 years ago on several gigging type amp/speaker boxes didn't crack or do anything weird. I was amazed that for my first try it even worked. Some people say to use boiled linseed oil and others say don't I didn't on my varnish and there's several violin makers who say they would use it so next batch I'll use boiled for the fast drying characteristics, hopefully it won't do anything I don't like. I think the non-boiled is used for food prep things like cutting boards and kid's toys as a health concern you wouldn't have in a speaker box or a set of drums.

I found some online discussion of a 1550 Italian recipe which said to heat 2 parts linseed oil with one part pine resin and one part gum mastic. The gum mastic is this stuff that comes from trees on one island on Greece that people use for chewing gum and a zillion other things. I found some so I'll try that. They also want you to add a small amount of alum which is this stuff they use in pickling. It's all findable so that's what I'm going to try next.

So thanks for the info and it's kind of like learning to play music where you need to listen to all kinds of people and then find your own way of doing it. There's no real right or wrong.

Another easy finish I've read about that has some promise is Tried and True Original formula, which is a linseed oil/beeswax formula. The main thing is to not cover the musical instrument in Saran Wrap, which is what modern polyurethane finishes do and it kills the sound.
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Barry Daniels
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Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Homemade Pine varnish

Post by Barry Daniels »

Have you heard about Tru-Oil. It is a thin wiping varnish designed for gun stocks. But it has been used successfully for guitars. It can be applied as a few coats to look like a thin, hand rubbed finish. Or a lot of coats with subsequent sanding and polishing to look like a high gloss finish. You can buy it a wally world in the sporting goods section.
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Alan Carruth
Posts: 1265
Joined: Sun Jan 15, 2012 1:11 pm

Re: Homemade Pine varnish

Post by Alan Carruth »

Heating polymerizes the linseed oil and makes it indigestible. That's why it's not used in food. For painter's linseed they often roast the seeds which gives a better yield, but of indigestible oil. Starting with oil that has already been partly polymerized might alter the way it reacts with the resin. The metallic dryers they use in ' boiled linseed oil' are said to produce a more brittle film.

The alum in that recipe was probably to neutralize acid in the resin or oil.

I've gotten different readings on what Tru-Oil is. Some say it's a thin oil-resin varnish, or a mix of varnish, oil and thinner, and others say it's just linseed oil that has been heated in the absence of air to polymerize it. I have used it, and it does seem to form a better film than the hardware store oil, but maybe not as good as an oil-resin varnish. I don't have any long-term experience with stuff that has been finished with it. I understand from my gun making friends that you do need to renew it from time to time. It does feel nice on a guitar neck. BTW; you'll note that it comes in really small bottles. Once you open one the contents will all harden up fairly quickly.
Ian Taylor
Posts: 4
Joined: Sat Oct 13, 2018 5:26 pm

Re: Homemade Pine varnish

Post by Ian Taylor »

Thanks for your comments. I'm taking it all in.

I've heard of Tru-Oil and have not tried it. I'm a bit worried about stuff that goes into the surface and acts like putting a wet towel on a guitar.

Some people have suggested that the alum does something to lock the colour in. I found some pics I took about 8 years ago or so when I had a crappy camera. It's of stuff I made cabinets for. All the stuff sounded way better than it started. It was inspired by a website by a guy named Charles Altmann in Germany. I had to try out his ideas and I can't tell you how much difference it makes to make speaker cabinets along the lines of violins. You wouldn't cover a violin in carpet and expect it to sound good.

The pics are of a JBL pa speaker I reboxed (the horn was made of wood), a GK small amp, a BOSS micro monitor and there's a before after fading pic of the Art amp I reboxed. All these things I reboxed were products that I could tell had decent electronics but the boxes were making them sound obnoxious. The JBL had a metal speaker grille that coloured everything and the plastic horn was horrible. The GK and Art amps both had metal boxes that sounded like what a guitar made out of a garbage can would sound. It was hard to believe that these products came from good companies.

They all sounded totally different after the reboxing. For some reason they sound way quieter to, the box absorbs the hum.

There seems to be some sort of spiritual energy that comes off of the boxes after they get varnished. It's like the pine varnish already has the surface excited so when you play a note it reacts really fast. It feels very much like an acoustic instrument. It's magical.

This all, for me, started with a comment Jan Hammer made in a 1970's Downbeat magazine where he said something like "when you play an electronic instrument, you're actually playing a speaker".

These speakers, they are for musical instruments, not so much recorded music. So there's no attempt at flat response. The horn I made for my JBL cabinet is all non-symetrical, all my carpentry is pretty bad, but because it's nice wood and the pine varnish is nice it sounds better than the plastic horn that JBL made that was perfectly formed.

So today I got some hide glue from eBay, the kind you heat up in a pot.
Attachments
This is a JBL pa one 12 with a horn I reboxed.
This is a JBL pa one 12 with a horn I reboxed.
(LEFT) The GK amp before varnish and (RIGHT) a reboxed BOSS Micro monitor
(LEFT) The GK amp before varnish and (RIGHT) a reboxed BOSS Micro monitor
Here's the GK amp looking pretty grubby.
Here's the GK amp looking pretty grubby.
GK AMP AFTER AWHILE.tiff (392.93 KiB) Viewed 6018 times
Coating a reboxed GK amp with plums
Coating a reboxed GK amp with plums
(LEFT) right after I stained it with plums and (RIGHT) after a few months
(LEFT) right after I stained it with plums and (RIGHT) after a few months
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