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Equal parts Mineral spirits, Linseed oil, and varnish
Posted: Thu Jul 22, 2010 7:01 pm
by Sean Powell
In the thread 'Bad carpentry issue bigfredb stated the following:
bigfredb wrote:Equal parts Mineral spirits, Linseed oil, and varnish.
I (or more accurately my loving wife) has just stained 4 pine trestles and a pine rope bed. I was debating a modern polyurethane vs linseed or tung oil. I also have 5 red-oak glastonbury chairs I plan to complete before Pennsic and wanted a more period solution then polyurethane on those. On the way home I needed wasp spray so I went to the orange big box store for oil. They had tung oil, varnish and mineral spirits all in the same section so I picked up all three.
Does anyone have experience with this mix? Does anyone know if it can be done with tung oil rather then linseed? I assume that the mineral spirits dissolve the varnish and then evaporate leaving the wood coated. If the mineral spirits are kept from evaporating does the mix last between coats?
Any and all advice is appreciated.
Thanks,
Sean
Posted: Thu Jul 22, 2010 9:58 pm
by sha-ul
Posted: Thu Jul 22, 2010 10:00 pm
by Maeryk
Okay, the mineral spirits + linseed mix will give you a drying oil, rather than a "wet forever" oil. The varnish you are putting in will give it a gloss that builds.
What you are making is pretty much a commercial, gloss, boiled linseed oil product, at home.
It works fine, but takes some time. This isn't something you are gonna slap four coats on in a day and take it out camping the next day.
It takes me roughly a week from last sanding to finished, assembled product on one of my chairs.. because I have no less than, and possibly more than, four coats of drying oil on em.
Posted: Fri Jul 23, 2010 8:11 am
by Sean Powell
Sha-ul, thanks for the bump.
Maeryk, (and everyone)
Thanks! I have aprox 1 week until I want to bring the trestles and bed to Pennsic for landgrab weekend. That means packing in 6 days. I hope to finish the oak chairs this weekend which will give me just under two weeks to sand and oil/varnish. I need some experienced advice:
Should I 'drying oil' or 'stay wet forever oil' the bed and the trestles? I need to start this TONIGHT (It's a quiet evening garage project so it's good after my daughters bedtime while the basement saw projects have to wait until Saturday)
What are the pros/cons of each in terms of application time, drying time and durability? I specificly want the feet of the pine bed and pine trestles to not wick up moisture if Pennsic turns wet (Tropical storm Bonnie should make landfall Monday and be broken and past Pennsic by Thursday but night zero and setup could occur in wet fields and I camp in the bog). Also, I can do a final coat AT pennsic if necessary assuming the wood doesn't get so wet that I'd be trapping water in instead of out.
I'm out of my experience depth on this one and appreciate the advice. I'm really debating chickening out and just going tung oil because it's what I know.
Thanks in advance!
Sean
P.S. still need to know if I can substitute tung oil for linseed oil. If not I need to swing by woodcraft on the way home today.
Sean
Posted: Fri Jul 23, 2010 8:20 am
by Maeryk
Sean Powell wrote:Sha-ul, thanks for the bump.
Maeryk, (and everyone)
Thanks! I have aprox 1 week until I want to bring the trestles and bed to Pennsic for landgrab weekend. That means packing in 6 days. I hope to finish the oak chairs this weekend which will give me just under two weeks to sand and oil/varnish. I need some experienced advice:
Should I 'drying oil' or 'stay wet forever oil' the bed and the trestles? I need to start this TONIGHT (It's a quiet evening garage project so it's good after my daughters bedtime while the basement saw projects have to wait until Saturday)
What are the pros/cons of each in terms of application time, drying time and durability? I specificly want the feet of the pine bed and pine trestles to not wick up moisture if Pennsic turns wet (Tropical storm Bonnie should make landfall Monday and be broken and past Pennsic by Thursday but night zero and setup could occur in wet fields and I camp in the bog). Also, I can do a final coat AT pennsic if necessary assuming the wood doesn't get so wet that I'd be trapping water in instead of out.
I'm out of my experience depth on this one and appreciate the advice. I'm really debating chickening out and just going tung oil because it's what I know.
Thanks in advance!
Sean
P.S. still need to know if I can substitute tung oil for linseed oil. If not I need to swing by woodcraft on the way home today.
Sean
I'd go for the drying oil, personally.
you can build coats with it a lot faster, and it's dead simple to "repair" the inevitable scuff.. just wipe some more on.
NEITHER of them is waterproof though.. something to keep in mind when camping. Several of my chairs have to sit in the sun for several hours if they have been rained on, before they will collapse without major effort, due to swelling of the wood. (Red oak, also, is particularly bad about wood movement, but one works with what one has).
I'd reccomend sanding your parts up to about 600 (if you are gonna sand) wipe em down with a damp sponge, sand the raised grain again, and go to town. I simply use Watco Danish oil or Teak Oil (depending on what the end purpose is). I set up "racks" get a tub, mix it, pour some in the tub, put on gloves, grab an old diaper and wipe it on, liberally, working my way through all the pieces. At the end, go back and look, and you'll find some areas that look dryer than the rest, re-apply there, then just let em sit overnight. Next day, (when they dry to the touch, and the smell is fading), give em another coat.
Then I give em another day to dry, assemble, and ready to go, after touching up anything I bunged during assembly.
There's an old trick I read somewhere for the feet of the trestles and bed.. assuming you didn't make crossgrain "caps" for them, which is to let them sit in a cup of some penetrating waterproofing type finish.. which will (in theory, I've never tried it) wick it up into the grain, and seal it.
You could also simply use a good poly on the bottom inch or two, and grain face, of the feet, and be done with it.
Posted: Fri Jul 23, 2010 8:58 am
by Sean Powell
Thanks Maeryk, thats great news!
Ok, not going down to 600. They will get a light hand-sanding at 180 or 240 now that the stain has dried. This isn't food-grade, they are camp furniture and probably too smooth to be authentic already.
It seems there is nothing magic about linseed oil and I have the tung oil so I'm going that route. My wife has generated enough linen scraps over the past 2 weeks that we were thinking of stuffing a camping pillow with them. Alternately we still have night-time diapers as emergency supply for my daughter who hasn't needed them in months. (YAY!)
Depending on how things look on Monday I'll polyurethane the bottoms of the feet for a little extra water resistance.
Thanks much!
Sean
Posted: Fri Jul 23, 2010 9:00 am
by Maeryk
Sean Powell wrote:Thanks Maeryk, thats great news!
Ok, not going down to 600. They will get a light hand-sanding at 180 or 240 now that the stain has dried. This isn't food-grade, they are camp furniture and probably too smooth to be authentic already.
It seems there is nothing magic about linseed oil and I have the tung oil so I'm going that route. My wife has generated enough linen scraps over the past 2 weeks that we were thinking of stuffing a camping pillow with them. Alternately we still have night-time diapers as emergency supply for my daughter who hasn't needed them in months. (YAY!)
Depending on how things look on Monday I'll polyurethane the bottoms of the feet for a little extra water resistance.
Thanks much!
Sean
Oh.. be INCREDIBLY careful with any rags, gloves, or spills.
Linseed and Tung oil burn down more shops than anything else.
Spread them to dry, outside, on a line or something. Just one bunched up linen rag can take out your whole garage.
Posted: Fri Jul 23, 2010 9:04 am
by InsaneIrish
Sean Powell wrote:
Should I 'drying oil' or 'stay wet forever oil' the bed and the trestles? I need to start this TONIGHT
If you are going to use the oil stuff, then use the faster drying oil. Going for "wet forever" is just that. I personally LOVE the look of linseed oil on wood. HOWEVER, this is the rule of thumb for applying it correctly:
1 coat a day for a week
1 coat a week for a month
1 coat a month for a year
Each coat should be "RUBBED" in with a nice thick terry cloth towel. You will get a nice sheen as you rub it in.
So, if you have something really nice that you want have a super awesome "satin wet finish" look to it, do the linseed oil. If you want something quick and waterproof don't do this.

I specificly want the feet of the pine bed and pine trestles to not wick up moisture if Pennsic turns wet
acrylic paint or clear poly coat the ends (parts on the ground).
I'm out of my experience depth on this one and appreciate the advice. I'm really debating chickening out and just going tung oil because it's what I know.
Something I have had pretty good success with is using deck sealant/exterior stain. I use it on alot of my outdoor camp stuff. The exterior stain (most of the stuff anyway) has built in waterproofing like thompsons water seal stuff. If you get the tinted stuff you can stain and "waterproof" your stuff all at once. I usually do 2-3 coats, The first 2 coats about 2 hours apart, the last I wait 24 hours before applying.
The finish is much like straight stain, not much gloss at all. There will be an "oily" feel to the pieces for a bit but that goes away. It is not the most period option but it is fairly cheap, I can stain my work at the same time, and I can re-apply as needed.
Might be an option for pieces that you know will be out in the rain.
6 board chest is "white oak" exterior stain on it:
Plywood chair with "cherry wood" exterior stain on it:

Posted: Fri Jul 23, 2010 1:05 pm
by ^
The Encyclopedia of Wood by the USDA has statistics on the effectiveness of various finishes. Unfortunately it only goes to like 3 coats and effectiveness for 14 days I believe. Our copy is out at the farm.
Posted: Fri Jul 23, 2010 2:20 pm
by Jeff J
BOILED Linseed Oil, ya?
Regular stuff take a long time to dry - better for tool handles & the like.
Posted: Fri Jul 23, 2010 4:01 pm
by ^
anyone make or use real boiled linseed oil vs the modern stuff?
Posted: Fri Jul 23, 2010 6:39 pm
by Jeff J
Piers Brent wrote:anyone make or use real boiled linseed oil vs the modern stuff?
Commercially? Not likely. Might find a "Boutique" manufacturer, but I haven't really looked. I could ask in one of the woodworker boards, if you really want some. I've considered boiling my own for experimentation purposes, but it's a tad less than safe.
(unlike casting with lead, which is TOTALLY safe...)
Posted: Sat Jul 24, 2010 2:57 am
by earnest carruthers
"anyone make or use real boiled linseed oil vs the modern stuff? "
I have made my own medieval varnish, very easy to make, as long as you are careful with the boiling.
I use pre-boiled linseed oil, in reality this is oil that has been chemically 'dried', most likely with metal salts, the metals accelerate drying time. As it happens this was also a medieval technique, in that cooking linseed oil in copper or brass pans (as well things such as ground glass and metal filings) was known to speed up drying.
Bring the oil to a steady boil, ie small bubbles rising, I add crushed colophony and cook until dissolved. The varnish should be cooked until it is 'stringy' ie it runs off a stick in 'ropes'.
You will find the varnish to be dark, dark from the initial boiled linseed and then darker from the actual boiling.
Proportions will vary according to the effect you want, more colophony means a shinier, harder varnish.
You can accelerate the drying of this varnish by adding genuine turpentine to your mix, this makes the otherwise awful smell of boiled oil and colophony that more bearable. The turps makes it more liquid and absorbent.
The varnish is the same medium for oil based painting, it keeps fine, stick a greaseproof paper sheet over the stored varnish and it will keep for a long time. Avoid sunlight.
For clear varnishes, the top end of the painter's medium, clear resins, for example gum sandarac (juniper) are used and the oil is not pre-boiled.
It would appear from documentation that a glossy finish was highly prized, adding lustre and shine, so the glossier the better.
If you are patient and live in a hot sunny climate, then you can 'dry' linseed oil in a copper basin by leaving it in the sun for a few weeks, or until ready.
There are more vigorous recipes, such as half filling a cauldron/pot and boiling the oil until it actually bubbles out of the pan and then setting light to it, no thanks!