Replies

1. 
   Gretchen | Jul 14, 2009 04:32pm | #1

   I can't access that but there have been a lot of threads about this concoction, basically saying "it isn't much". Do a search for more, but here is what Steve said on one.

   was a long thread on the Hot Rod Varnish shortly after the article appeared.  It begins at  41228.1    At the end of the day, it is still an oil/varnish mix, and as such would be relatively soft if allowed to dry on the surface.  Consequently, it won't work well if you don't wipe off all the excess.  

   I would stick with a wiping varnish.  Any wiping varnish will be more water resistent than this mixture.  You can avoid the plastic look by doing two things.  First, don't get the film very thick.  A thin varnish film won't provide as much water resistence as a thick one, but more than an oil/varnish mix.  Secondly, you can avoid using a polyurethane varnish, which gets plastic looking with a thinner film than with varnishes using alkyd or phenolic resins. 

   Gretchen
1. 
   Samson | Jul 14, 2009 04:39pm | #2

   Thanks, Gretchen.  I get the sense Steve doesn't like oil/varnish mixes in general.  I'm past that debate here.  What I really want to know is whether odorless mineral spirits are materially differnt thatn turpentine as a thinning agent in this (or for that mattter, any) oil/varnish wiping blend?

1. 
   SteveSchoene | Jul 14, 2009 06:52pm | #3

   I like oil/varnish mixes, as long as it is realized that they are strictly "in-the-wood" finishes that shouln't build a surface film.  Great for modern, casual looks.  Particularly suited for open pored woods such as oak and walnut where filled pores and a formal film finish would be too heavy. 

   As far as the differences between pure gum turpentine and odorless mineral spirits, the mineral spirits will generally evaporate more quickly which may affect ease of application, particularly in warm weather. 

   Turpentine may have a bit more solvent power, but in virtually all applications it's not the solvent power that is relevant, it is the use as a thinner.  In those cases they will be very similar.  Turpentine may also have a bit more trace resin residuals but I don't think they would make much difference one way or the other. 

   The problem with the Hot Rod Varnish is basically it tries to make an oil/varnish mix act like a varnish, basically through excessive additions of metallic driers.  I therefore am suspect of the long term durability of the finish, especially in comparison with straight wiping varnishes, which have every reason to work well.  I can't see any offsetting benefit to exchange for giving up the durability.  With ordinary oil/varnish mixes, you give up the durabiliyt and looks of a film finish, in exchange for an appearance that can be preferable for many styles, and for the ease of application and of maintenance.   

   Edited 7/14/2009 11:57 am ET by SteveSchoene

1. 
   Samson | Jul 14, 2009 07:00pm | #4

   Thanks, Steve. 

2. 
   Samson | Jul 14, 2009 07:06pm | #5

   Oops you edited while I typed a quick thanks, but your edit raised questions for me.

   If I wiped BLO on some cherry and let it cure well, do you think I should just thin some P&L 38 then and use it as a wiping varnish with no japan drier or other oil?  I've never used P&L 38, but have acquired a can at this point in anticpation.  Will the resulting finish be as easy to repair as Roland's version?  I had assumed the P&L 38 alone would make more of a film that would require full on sort refinishing if damaged? 

   Edited 7/14/2009 1:31 pm ET by Samson

1. 
   SteveSchoene | Jul 14, 2009 10:13pm | #6

   Yes, you could do exactly that.  The resulting film will be more durable, needing less repair.  I'm not sure that repairing problems would end up being more difficult.  Certainly not as easy as an oil/varnish where there is no film, but once a film exists of a material that isn't redissolved in it's thinner, then repairing will be similar. Either finish would require full refinishing for serious damage, but either could have minor damage repaired in the same way, by patching and blending in the new material during a rub out of the area. 

   Polyurethane varnish would be harder because of more concern about adhesion of new to old, but that's not your issue here. 

2. 
   Gretchen | Jul 15, 2009 12:20am | #7

   Steve has answered well, and completely. Just because you "can" mix up something and put it on wood--AND get it published--doesn't mean it is a good finish, which is what I believe Steve addressed very well.  ;o)Gretchen

3. 
   brucet9 | Jul 16, 2009 10:07am | #9

   Odorless mineral spirits is such a poor solvent that you would have to use considerably more in order to achieve the same viscosity as the original turpentine "recipe". The result would be lower solids and much longer dry time.BruceT

2. 
   DougF | Jul 15, 2009 08:05pm | #8

   I wish I could find the document related to the properties of turp but I've misplaced it somewhere in the ether: bottom line, unlike other solvents, a portion of turp chemically combines with the resins in the oil to create a modified bond.  The remainder gases off.  I use a mixture of BLO, raw tung, turp and varnish for my wiping finish and I have been extremely pleased with the ease of application , the finish and durability over time.   The odor is rather strong but only lingers for a short time.

   For what it is worth, odorless mineral spirits is at the very bottom of the distilling food chain.  What that means is simply that it is less effective as a solvent compared to others.

   Doug

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   Edited 7/15/2009 1:05 pm by DougF

   
   

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   Edited 7/15/2009 1:09 pm by DougF

3. 
   dkellernc | Jul 16, 2009 08:06pm | #10

   Sean - I'll note my experience with odorless mineral spirits vs. "regular" mineral spirits - it may have some applicability to what you're going to do.

   I needed to thin out some minwax gloss polyurethane to form a wiping varnish.  Not wanting to stink up the shop, I used some Kleen-Strip odorless mineral spirits (freshly opened can) to thin out the poly.  Within about 12 hours, a substantial amount of the mixture had settled onto the bottom of the jar as a thick, gel-like substance, and it would not go back into solution regardless of how vigorously it was mixed.

   I'd had good luck with "paint thinner" ("regular" mineral spirits) before, so I re-made the mixture with that.  No problems - and it is still a homogeneous solution several months later.  I checked with Kleen Strip to see if the "odorless" kind had any substantial quantity of water in the mix, which would be expected to polymerize polyurethane, but the customer service rep said that it had less than 1/2% moisture content by volume.

   My guess is that removing some of the PNAs and the low-boiling alkanes in the "regular" mineral spirits to form the odorless kind has a deleterious effect on its solvating power.

1. 
   Samson | Jul 16, 2009 09:15pm | #11

   Doug, Bruce, and Dave:  Thanks to all of you for your input.  It sounds like I'd be better off trying to just rig some fans or finishing the piece on the porch than trying to mess with odorless mineral spirits.   You da men.