Thread: Japanning Comparison - Cold Mix vs. Run (hot combining like varnish)

that will lead to the run version, which is going to be:
* heating the asphaltum resin in a pan to about 500F for an hour or two. I think this resin is very clean, so it's not going to be the poo-show that running a natural varnish resin can be. Clean means what's in it that needs to cook off should be very little. not so with copal and some other varnish resins that can have a lot of volatile stuff that needs to react and bubble off for hours
* heating the oil and combining with the asphaltum and cooking around 400-450 for an hour or so
* testing the oil and resin mix to make sure it strings (the sign that two components have linked to create a long chain polymer)
* If string is successful, cool mix to about 250F and add turpentine (danger if anyone tries this - fire can happen at any step, but if you get too quick adding turps much above temp, you can have fire).


This will create a varnish that is stable and doesn't separate, but the ash and such should still be able to settle over time.

if I fail at this, I will post that, too.

The desire with this is that, if i can get oil and resin to crosslink and make it a "real varnish", then:
* it doesn't separate in the jar
* it still has no driers in it, so it shouldn't gel in the jar or form a really thick skin
* the mix itself is crosslinked but can still be baked in a toaster oven for tools
* it can be used as is after adding driers to make a cold brushable varnish that should dry in a day or two without a bake if desired
* if I'm on the mark, the ash and other junk will eventually be in the bottom of the jar, and it should create a very good finish without little bits that will stick up in an otherwise glossy layer

*all of this running of resin and cooking varnishes must must must be done outside. Even good linseed oil will smoke at high temps and off gas and many of the various natural resins when run will give off toxic vapors. no clue of gilsonite asphaltum will also do this. Petrol bitumen might, but we absolutely are not going to use that in a high quality varnish - it's filthy and full of sulfur and other things and is intended to have a low melting point. You can use derek's recipe if you want to do something like that and just use it as a colorant in a commercial boat varnish - if you need to apply a cold varnish and just don't want to do anything, that's much better than paint. But it's also true that a fine black (lamp or furnace black) would be better to use than petrol bitumen.

fire, stink and injury are all possible when cooking varnish because the temperatures are very high and accidental introduction of something with even a little bit of water in it can lead to steam tossing stuff or burning/fire if temperature gets away from you.

Originally Posted by D.W.

So, before I mention the run, here is a first picture of three spokeshaves that were basket cases:
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So.....all of these completed shaves are actually great, they have a fantastic feel and the japanning is tough and over the years, it will continue to oxidize and get harder as the finish crosslinks more and more. If you just want to do planes, you'll be able to do a million of them with a pound of asphaltum. It would have to be in the range of 100 various planes and shaves for one pound of the stuff, and the mixing is easy.


My mix (just repeating the one I used from the internet)
* real pine turpentine ordered from portugal - the US option for real turps (diamond G) will be a no-go in australia. it's already expensive here. - 50% of the final weight
* gilsonite powder - 30% of final weight - dissolved into the turps. Various recipes mention weight vs. volume - I think you want weight
* linseed oil - 20% of final weight - wait until the gilsonite is dissolved for a day or so after shaking the jar off and on before adding the oil
* thin to the final desired level with additional turpentine if it's too thick, and strain into other jar through paint strainer

I've ordered a pound of gilsonite, which is too much (need another 999999 planes!), but I'll be happy if I can get the same result as your top spokeshave. I'm not 100% confident on running resin, so I'll go with the cold mix first and see how I go.

Thanks very much for all of your advice/experiments, DW! Hopefully I can get a nice result and post some pics here.

excellent. I don't know how fine it can be screened, but once you run it through something like a 200 grit paint filter, there's not much left big in it.

I've got some waiting to do to see if running it over lunch today was a success. I ran it at 500F for a while and then combined oil and cooked both parts together for a while longer - unattended outside. the resin itself is pretty clean, but the little gritty bits are still in there - some on the bottom of the run pan, but some remain in the varnish that are smaller than the paint screen.

Point being with this, if you have the cold-mixed stuff and use it, I think you'll be doubly pleased with it and it takes about 5 minutes of time and not breathing (even outside it's harsh) very stinky fumes that can only be avoided by standing outside wearing an organic vapor mask.

I discounted Steve voigt's mention of wearing a mask outside when cooking a resin that needs a high temp run, but I get it now!!

I'm very pleased with all three of these spokeshaves after separating myself from wanting absolute mirror perfection at first. None of it has been a waste of time .......except, I guess, there's a chance that running it and trying to link the oil and resin will be a failure if it didn't work. if it didn't, it's just more cold mix and the oven will finish the job.

Running resin sounds manageable from your description. I'll wait to see your results!

Not sure how easily obtainable Portuguese pine turps will be but how about gum turps?

Back in 2004 our Benevolent Dictator had this to say about it:

Pure (gum, wood) Turpentine is derived by destructive distillation of wood and contains mainly pinene and dipentene. It is a known sensitiser (not a good thing) and may manifest itself as a skin rash or inflammation or as an asthmatic condition, and in some individuals this reaction can be extremely severe. It is also thought to be a cause kidney failure if abrorbed through the pores of the skin. It can cause many mental problems and is one of the reasons why so many of the great artists were certifiable nut cases. Don't be fooled into thinking that natural is always better. Often times is definitely is not. :eek:

Mineral turpentine is a refined petroleum solvent and is a mixture of straight and branched chain paraffins, naphthenes and aromatic hydrocarbons. Basically it aint anywhere near as bad for you as the other stuff.

Hazardous material bit aside; would it be a suitable product to use in lieu?

am I understanding that petroleum distillates are being referred to as "mineral turpentine"? Could be "white spirit" in the UK or Naptha here or mineral oil (not sure what they call that in the OK, some analouge of stoddard solvent - not sure of the overlap).

if so, yes, that will work in place of the "real" turpentine.

I mention the portuguese seller because they list on ebay and sell to the US and their turpentine is as good, at least as far as I can tell, as the Diamond G turpentine which is sort of the standard here for artists and varnish makers (as in, very small industry of folks who are picky - a lot of the varnish crowd outside of boat types is aimed at art and orchestra instruments).

At any rate, the old texts from turn of the century do mention using "benzine" (naptha/white gasoline) as the solvent for some of the japanning mixes. They don't seem to discuss it vs. turpentine, at least not that I picked up.

Gilsonite definitely dissolves in naptha, though. Too, it looks like naptha has a flashpoint and autoignition temperature similar to pure turpentine.

For us, the option is there also to use the stuff sold by Klean strip, which is turpentine but it stinks instead of smelling like fresh pine. I guess from the text you posted, that option is out. I tend to use the cheap stuff more for cleaning brushes - as cheap as I can be sometimes, the smell difference is worth it when working with varnish.

The SDS for turpentine would just about make you believe you were working with hydrazine.

It depends on how well ventilated your workshop is, but in my case the home store turpentine smells so strongly that it migrates to the rest of the house, SWMBO complains.

Whatever the source, actual turpentine may be a better starting point if you are indoors, semi-indoors or outdoors, the chrap stuff stinks.

I went ahead and applied one more coat to my Birmingham block plane. It didn't make it worse, it's done now.

I mentioned to David the other day that I have a Stanley sweetheart era #80, it is remarkable to me because of the state of the japanning. It was stored, since I don't use it, it has more dings than I remember, I think it wasn't or had very little use. The handles look really smooth, but not as good as the Singer sawing machines. Here are pictures next to my freshly japanned block plane.

Rafael

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I wonder what it was stored with. If it had been used heavily, the shine would've worn off of the parts that hands were on (dirt on hands, etc).

Japanning takes rub marks easily, but at some point when it's handled enough, it all looks about the same. Before just running the last shave through the forge, I never thought about just how well it's adhered, though. We knew it was better adhered than paint and more shatter resistant, but I've never encountered a finish that an electric heat gun wouldn't bubble. it ashed off pretty easily once the induction forge heated the cast, but i'm not aware of any coating that would tolerate that level of heat.

there are two things that happen with varnish over time - the bonds continue to polymerize, and then to some extent, the established bonds can be interrupted (by UV light, etc) and some part of it degrades. I have no idea what proportion of those things occurs, but the japanning on the last shave was not to be removed with anything normal. not oven heat and scrape, not die grinder and steel wire brush.

Stripper is the only thing I've seen that makes it lose its constitution quickly. It could be that a soak in naptha or something would break it down over days, but that's not very practical for a plane.

to add to raffo's point about smell - i find the turpentine smell pleasant...the "good stuff" that is, but my garage shop isn't super tight. It's tighter than an old shed, but the door is not (intentionally) a modern weather sealed this or that.

The strength of the smell is moderate and I don't notice any smoke at all at 450F.

Important maybe to mention that if you use a toaster oven or something with exposed elements, you should have a shield between those elements and whatever is being baked - my oven thermometer shows drastic temp swings up into the 500s in the toaster oven and it could burn gilsonite.

anyway, more to the point - I would do a plane in the oven with the window open and a fan upstairs, but only because the smell isn't that unpleasant. If you don't care for the smell of even good turpentine, it'll be very undesirable. if you get the asphaltum to smoke somehow based on what I smelled running it, it's a no go inside. the smell was *strong*. Like campfire type smell that sticks to you - burning pavement, and so on.

The point that it smokes like that is >450, though, and you won't have any of that same smell if the temperature is well controlled and stable.

may be academic if you can't get good quality pine turpentine there.

I suspect what happened in the US if it wasn't a regulatory decision was a wink and a nod to get rid of turpentine. The cost of mineral spirits and petroleum distillates has pretty much eliminated the use of linseed oil in regular paint use. it's almost humorous how glowing the view of great clean linseed oil is in older texts because of it's ability to polymerize, crosslink and then be very stable and tough when used in finishes....and the view of linseed oil in the US is that it's a cheap hardware store oil.

I wonder if that was marketing. Some of it has to do with color where putting a clear finish on a white wood has been popular, but it's dead looking and unnatural to me. I haven't seen as much talk on forums in the US as we used to but constant was "how can I get maple to stay bright forever and have a finish with no color". It's now a bit of a dated look and has given way to white, which fits into my view of kitchen and bathroom turnover - colors go by about a 20 year cycle or so. Often enough to make your kitchen look out of date if you followed advice when it was made. In the late 90s, I worked in a cabinet factory. Light oak was the rage, but white was the non-clear finish rage, and maple with a finish with no toner was just gathering steam. I think the latter is still in style, the light oak is totally out (especially red oak), and white cabinets went by the wayside for a little bit and are now back.

I sure hope lacquered brass plated hardware doesn't make a comeback.

day two of the run varnish - or one day elapsed. it seems like the top layer is identical yesterday, and not becoming oily. Long time to go to ensure that it doesn't separate, but good so far.

it's also true that the remaining little grits that are in the varnish are still there - i wonder if those insoluble parts are the same density as the resin or the cooked varnish, or close enough that they don't move. Last night, I ordered a 400 grit stainless screen (princely sum of $14 for enough to probably make a dozen strainers, and when used for varnish, any solvent will take care of it and stripper would clean it later if it's forgotten. So hopefully this will mean a permanent pair of strainers).

At any rate, i want those grits out.

Talked to Steve Voigt who you guys may recognize as a planemaker, but he's working on developing organized content (foreign concept for me) on how to make natural resin varnishes in the modern era, and I asked him about stringing. he confirmed that once you add a bunch of turps, stringing is over - the stringing test is during the cook, and there is stringing and for varnishes that are too dense to string without breaking "pilling". Well, this stuff does all of those when combining oil and resin, but it's hard to tell because the resin does some of those things on its own - only difference being after the resin itself dries, it's brittle.

Cleans up easily with naptha after the cook (or gasoline if needed) until the varnish cures a lot and becomes less sensitive to solvents.

cold mix still the practical value for anyone looking just to japan planes. I want to be able to "paint" this with driers and have that brilliant black finish.

If a 400 grit stainless screen doesn't make it a lot smoother, i guess I'll have to figure out something else. this smoothness at this point is no issue on castings, only on bare very flat and true metal.

One more block plane, right off the oven. By the way, I'm using an old electric toaster oven with a convection fan. According to the inexpensive oven thermometer I placed in it, the maximum temperature I'm achieving is about 420F, in convection mode, all other modes are cooler.

The block plane body had mostly good japanning, so I didn't strip it. I put a coat at the front and sides.

There's no stark difference between the retouched parts and the old japanning, the oven didn't damage it either.

The cap was stripped and has at least 3 coats. I tried to strip the cap with paint thinner, but after over 24 hours of soaking, there was still quite a bit of hard japanning left. The paint stripper did the job very fast, but it was messy. In any case, it worked.

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It's cool now, still works rather well edge planing pine. The crack on the cheek is how I got it.

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Rafael

the cooked version of this has now resided in a jar for several days, and instead of separating and perhaps getting thinner at the top, it has gotten a little thicker. Not curing on the surface, but thickening a little bit. That's a good sign as far as I know - that something is continuing after the cook perhaps. The asphaltum should've been dissolved and fully combined with the oil already, but the length of the bonds between the two ...could it continue? Is that why most varnish recipes say to make the varnish and then put it aside for a month or longer?

Don't really know.

last item that I have that needed new japanning is in the toaster oven - a stanley 80, which is a tool I don't use too often, but I do like to use it to remove finishes sometimes. It's hard for it to do it's wavy surface thing when the finish being removed lets you know when to stop.

I favor the cooked version at this point, of course, but still don't think anyone should go out and buy two pots that they will not use for food again just to make it.

Cooked varnish yesterday, too - that went a little less well as far as I can tell. combining the gilsonite and oil was a lot smoother than making most varnishes in general.

it occurs to me as this mix seems to be strong as far as viscosity goes, there may be another thing to bet on at lloyds. I'm assuming that this is a good thing, but I have no evidence that since asphaltum isn't really the same as a natural tree resin that it won't harden in the jar over time and become a big rubber brick.

that'd be unfortunate.

the other thing that's interesting, but more to me than probably anyone here is that the cooked varnish is now crosslinked asphaltum and oil, so the phase of smells is missing the nutty oil smell.

With the cold mix, you'd get turpentine flashing off, then you get a nutty oil smell and that dissipates probably once everything crosslinks.

Now there is no separate oil, so there is also no nutty smell. I thought at first maybe something was wrong,

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