Gidday Peter
My name is Luke and I live in a place called Wagga Wagga New South Wales in Australia yup thats right down under!!! I’d like to thank you for all your contrabutions to the fine woodworking network and want to let you know that I am a keen reader of your articles.
I’m presently attempting to perfect a Tung Oil Finish with pretty disasterous results. I’ve found theres lots of conflicting approaches and techniques so that it was time to ask an expert.
I’m presently attempting to finish a fairly open grined timber native to here called Mountain Ash which is a moderately hard lumber. The grain is usually straight; the texture is rather course, open and even growth rings are often easily visable and it can be worked to quite a high polish and takes most finishes well.
The preparation I have attempted is:
Sand through the grades upto 2000 grit wet and dry hose down with compressed air then take my stock to my finishing room and wipe down with a tack rag.
I have then been dousing a clean rag with pure tung oil leaving a liberal amount on the stock for a couple of hours then wipe off leaving to dry for at least 3 days.
I have applied 4 coats using this technique with poor results but plan to continue using this process in an attempt to get the grain to POP!
Could you please give me some tips on Applying a Tung oil finish? SHould I be applying a thin coat or a heavy coat? should I mix the Tung oil with a thinner to promote faster drying? How long should I leave the tung oil on before I wipe it off? how many coats should I apply to my stock to get the best results?
Your help with this one would be truely appreciated
Regards Luke
Replies
Gidday Luke,
I'm glad you like the forum and articles. It's good to know we're helping.
I had the opportunity of teaching one of your fellow countrymen finishing a couple of years ago. He was in Boston at the Noth Benett Street School and completed a two year program. He and another student came in my shop for a couple of very intense Saturday sessions with their furniture. It was fun teaching two very talented and motivated individuals. I understand when he got back " down under" he won an award for his work.
Concerning your questions on tung oil;
First off you're sanding your wood way too much. I wouldn't go past 220 at the most.
After you've got it sanded and cleaned , wipe a fairly liberal amount on your wood. As it starts to absorb in areas, try re wetting it a little. After about fifteen minutes or so, briskly wipe the surface down. Go back every once in a while for the next hour or two and wipe off any residual that weeps out of the grain. If it gets a bit sticky, dampen a rag with mineral spirits and wipe it down and dry behind it. BE VERY CAREFUL WITH OILY RAGS. Spontaneous combustion can certainly ruin your day.
Let it dry for a day or two. For the next coat, apply some oil to the surface and this time rub it in with 600 grit wetdry sandpaper. You'll develop a slurry as you go along that will also fill the pores. Do this in manageable sections and wipe clean as before. Don't forget to come back in a while and check for weeping. Do this a few times and you will have a very satiny surface. Remeber though, tung oil does not give you a surface build and will always have a matt surface.
Concerning grain pop; have you considered a dye or stain? You could also add a little artist colorant to you oil to promote some pop. If you do this, blend the colorant with some thinner first to liquefy it. Next, add it to a small portion of the oil in a separate container. Strain this mixture and you can then add it to your oil. Experiment a little and make some samples. You may surprise yourself.
You can also add some thinner but this just reduces viscosity. Remember, tung oil dries by oxidation not evaporation. You can always add some japan drier to it to help promote oxidation. Don't overdo it with the drier. One to two percent is enough.
Good luck and let us know how you do.
Gidday mate,
Peter Gedrys
Gidday PeterThank you so much for your invaluable advise.It was great to hear that you have had some positive experiences with aussies in the past :-)N although some distance away I hope to become a keen student of yours also!!!How thick a slury should I aim to make when sanding with the 600 grit wet/dry??? Should a sand just until a slury starts forming or continue until a noticable slurry forms that can be really worked into the stock.ARe there any disadvantages to sanding as much as I am? I've got a lot of conflicting information in regards to sanding n there appears to be 2 schools of thought Firstly to prepare the surface as much as possible before applying a finish and secondly to only finsh upto 220/320 grit .WHat are your thoughts on this issue Peter?It has been a real pleasure for me that you have taken the time to converse and provide expert advise once again thank you so much for you timeYours sincerely Luke
Edited 8/25/2006 6:58 am ET by Lou2u
Luke,
Concerning wet sanding; Apply some oil and sand it in. A light slurry will form. If it gets too thick, wipe it off. This is where, in finishing, the questions stop and the work starts. There is NO substitute for experience. Make some good size samples and you'll see.
If some people want to sand to 2000 grit, let them. To me it's a waste of time and frankly, not much fun. For me 220 is the most I need and as I build my finish coats, sand in between each coat for more refinement of the surface.
Let me know how you do as you progress. Just don't waste a lot of time doing unnecessary sanding.
Peter
Gidday PeterHeres my first attempt........... 7 coats of tung oil finished off with a cut n polish. Really appreciate the advise throughout my baby steps in learning how to 'Tung'.Next attempt I'll work on getting a thicker slurry with my wet sand and perhaps play around with a few dys n stains to see if I can get some grain 'POP'OH YEAH & of couse reduce my sanding!!!!!!!See 'Pic' for final result.REgards Luke
Edited 9/5/2006 3:50 am ET by Lou2u
Gidday Luke,
Nice job. I'd say you've got the hang of it. Keep playing around and keep me posted on your progress.
Regards,
Peter Gedrys
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