GREEN WOOD SANDING AND FINISHING – Some thoughts (Terry Scott’s – New Zealand)
Turn green wood thin and then sand 240 grit as you normally do, then sand with Odina oil (food grade medicinal paraffin oil) through to 400 grit, alternatively wet sand with water and a solution of 10% dish detergent through to the finish grit. You will not have to go back to sand when dry. Getting the compressed torn grain out if you only sand when dry is almost impossible.
Then wrap the piece in newspaper and store, for one or two weeks for very thin pieces to 3 or 4 months for thicker wall pieces. Then take it out of the newspaper and leave another month. If you are spraying over oil, dampen a cloth with thinners and rub your piece, then let evaporate thinners and spray with 50/50 thinners and lacquer, 30 % gloss is the best.
TRANSLUCENT PINE (David Chung – Hawaii)
For small pieces: use a 5-gal. plastic pail that once contained paint can be for a soaking container, using the same lid to help reduce the vapor loss from the volatiles in the paint thinner. The chemicals will dissolve some plastics, so the type of plastic barrels you use need to be selected carefully. For larger pieces, you will need to improvise to get the proper container. I have seen some heavy-duty trash bags lining large plastic garden barrels. The Watco Danish as well as the Russ Fairfield recipe will eventually turn to a gel, but not until about 1-1/2 to 2 years of use. The consistency will thicken and eventually start to clump up and separate. Linseed oil is not as susceptible to hardening when exposed to air as pure tung oil is. Adding more paint thinner when it starts to thicken seems to extend the life "in the pot" somewhat, but eventually the mixture has to be tossed out as the solution will separate into solids and leftover liquid. To dispose, we are asked to absorb the liquid (lots of shavings available for this ;-)) and place the absorbed material (in a plastic garbage bag) in the container for regular trash pick-up.
Kelly Dunn’s Techniques for both Translucent Work and Regular Finishing
“ A Simple Finish and The One I Really Use”
“ I create my own Danish oil finish The translucence is mostly from linseed oil, but the problem is linseed dos not dry well. Use Watco Danish oil or mix a third boiled linseed oil, a third gloss polyurethane, a third mineral spirits (paint thinner). Immerse the finished bowl (I stop at 320 grit) in this mix until it has not changed for 24 hours. Three days to a week. I have a drip rack in my bucket (30 gallon trash can). Time it so you can dry the piece before your mix hits (starts to harden) on it. I like Bounty paper towels.
Time varies from mix to mix. Let the bowl dry. I use a home made kiln as it is so wet here (Hawaii). Next day, dip the bowl a couple of times. Let it drip, then dry it. Start watching it. If the mix bleeds to the surface, wipe it dry. I power buff all shiny spots. Use brown Tripoli buffing compound. Do this each day until you have buffed the entire piece.
That said you can see why not too many people want to do this much work for a bowl. The above works fine but is not what I do.
WHAT I REALLY DO: TWO PART PROCESS
My first mix is boiled linseed oil thinned with maybe a quart of thinner per gallon. The mix always needs tweaking over time. The dryers in the oil will evaporate over time. You will need to begin adding a few drops to a few tablespoons of Japan Dryer, depending on how much mix you have.
Start the process with a sanded bowl, as above. If the oil bleeds to the surface of the bowl when you hit it with the buffing wheel, you either need to dry the bowl longer or start adding the dryer. With linseed, if the bowl feels slick and oily it is not dry. Do not push the process or you will have a bowls with un-dried pockets of oil in the cell structure. It will bleed when the bowl gets warm.
The day the linseed no longer changes the appearance of the bowl (normally day 3 to 5), I then dip the bowl in a thinned down polyurethane. You can used a commercial Danish oil for this. My mix is poly, thinned down a bit with thinner and enough boiled linseed oil to give me 10 minutes of drip time before it begins hitting. I dip the bowl and let it drip on a rack for 10 minutes and dry it with paper towels and put it in the kiln. Always check for bleeding in the kiln or your drying space. The volatiles in the mixes can force the mix to the surface where it will harden – giving you a most horrible mess to buff away.
Do not use any Japan Dryer with the polyurethane. It will gel the mix. If you use varnish instead of poly in this mix, Japan dryer is compatible. But I have never needed any with this second mix.
This second mix will gel over time. Tweak the mix till you are happy with it. Know that in a couple of weeks you will have to start adding thinner. When the mix begins gelling, make a new mix. If you are only going to do this once in a while, put the mix back in cans and seal them to keep the mix from gelling. This double mix system of mine works for me. It is a lot of work and tricky. That is the main reason I hesitate to teach it. My experience has been that folks push this process and want to complain to me. Follow my instructions.”
(I have one of Kelly’s bowls, and, believe me, the quality of the finish justifies all the work he puts into it. It is superb. – Bill Neddow)