You should only be treating the outside of the hive, so really this will have no “food contact”. You may be right that it would not be suitable to treat the inside or frames with but we don’t treat those portions anyway.
My guess is for them to be able to label the product as 100% pure the amount of solvent would have to be less then or equal to .5%(thus allowing it to be rounded up on the label). If it were more then .5% I would imagine they would have to label it as 99% pure. Which would mean in a quart volume(960ml) of finished tung oil you would have 4.8 ml of solvent, which is about a teaspoon per quart. That is of course as long as my assumption about the labeling requirements are correct.
Ermmm, maybe your application skills are better than mine… Or maybe your boxes are tighter at the corners than mine… However, on every box that I have sealed, the Tung Oil wicks through the corners to the inside of the box, and spreads over the interior surface for a couple of inches sometimes.
So given my lack of precision sealing skills, I prefer to use food-safe products!
One thing on the MSDS that worried me, I quote, “The exact percentage (concentration) of composition has been withheld as a trade secret”, and Tung Oil is listed as 60-100%. With that kind of latitude in formulation, I would not be willing to risk it. But then as you know, I am a nit-picker with OCD!
I’ve done a lot of woodworking over the years, never specifically on a bee hive box, but I have never had that much wicking before with other oils or stains. That seems like an unusual amount of penetration, but I usually glue my corners on most box type projects I have done so perhaps that keeps excessive wicking from occurring. But I see your point, I still don’t think the small amount of added solvents would be much cause for concern in the concentrations they likely have.
A note on my method, I applied the Tung Oil with a brush, like Cedar does in one of the Flow videos. I do not overload the brush (my father was a paint chemist, and he would come back to haunt me if I did). I painted the only the outside of the hives in the upright position, as if they were in use. I wiped off any excess (not much) with a cloth after 30 mins. These boxes were treated about 6 or 7 weeks ago, so the oil is not wet.
It is interesting that you can even see oil penetration through a knot in the wall. You can also admire my metal frame rests!
The first coat was thinned 1:1 with food grade Citrus Solvent. The second coat was applied neat.
I have some mediums to stain, and my “real” Flow hive should arrive in the next 6-8 weeks. I didn’t care much for the potency and persistence of the Citrus Solvent smell, so for the next batch, I will only use undiluted Tung Oil, so I will let you know what happens with those too.
Just did a first coat with neat Tung Oil today on 4 mediums, 2 hive top feeders, 2 slatted racks, on outer cover and one SBB. All I can say is… where is the Naproxen/Alleve/wrist pain medication??
It was MUCH easier and faster doing a first coat with diluted Tung Oil. It took me over twice as long - I almost ran out of daylight. However, using neat Oil made it much less smelly.
No pain, no gain? I will leave it a week or so and photograph the inside of the boxes for comparison with those above.
Yes the extra deep is from beethinking. I’m thinking about getting a shallow to put between the super and brood to get some cut comb, but haven’t made up my mind. But I do love honey comb!
I use mediums for that. Foundation-less, then I use a comb cutter. The remaining edge scraps I just crush and strain - some people like “chunk honey” = comb in a jar of honey, so if I have a mix of liquid and comb, nothing is wasted, and comb or chunk honey sell at a premium around here.
However, on every box that I have sealed, the Tung Oil wicks through the corners to the inside of the box, and spreads over the interior surface for a couple of inches sometimes.
