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TOUCHDRY
5th September 2007, 12:22 PM
Howdy,

Just wanted to get some advice on what to do with our new floor. We just had 100m2 of 130mm Spotted Gum sanded and finished with Tung Oil (not the pure stuff)... but it has reacted badly, causing a bubbling effect which looks like the floor was covered in dust when it dried.
The finisher says it isn't his problem if the wood reacts (SG being an oily timber). He HAS offered to dust back the the top coat to flatten out of the bumps and re-do the final layer. My question is- will this work? Or is it just going to happen again?
Also- the finish is WAY glossier than I was expecting - is it possible to get the finish looking more satin? Or is that just the nature of the hybrid Tung Oils?

Thanks

jaspr
5th September 2007, 12:52 PM
hi touchdry

have you thought about contacting the manufacturer directly?

I say this because many years ago we had a poly finish on a large area of cork flooring bubble.

The guy who did it was right - it wasn't his fault. He'd been using the same product with no problems for years.

So he contacted the manufactuerer - and, yep - they were having problems with a particular batch. (To his credit, he actually sanded the first lot back and tried again - but with same problem. Then he called the manufacturer.)

Manufacturer replaced the product and covered the cost of having it sanded back and redone.

I know you are using a totally different product - oil based, not poly, but ... might be worth a try

dado
5th September 2007, 05:45 PM
G'day TOUCHDRY, At the vision-impaired woodworkers Club, I recently built my nephew a pianist's recital bench from Tassie Oak, stained it with a water
based Teak stain and finished off with several coats of pure Tung Oil. Before beginning, I was told, by the workshop supervisor, to liberally apply the Tung Oil with a lint free cloth, then wait about an hour or so, and then wipe off all the excess oil with another lintfree cloth.
To my later regret, I decided it'd be better to leave a thick coating on my work and speed the whole process by not wiping off the excess oil. On returning to my bench next day, I found the whole thing felt like coarse sandpaper and my first thought was that it was dust particles that had settled into the oil coating during drying. But no, it was that the excess oil had congealed into millions of tiny beads or droplets before completely drying. "Mia culpa -my fault! My supervisors mirth and derision at my expense cannot be repeated here, but it was merciless, even if well deserved.

After allowing my "messup" to go completely hard, another 2 full days, I was able to sand it all back to a smooth , albeit an almost un-oiled finish. from that point onwards I followed my supervisors advice to the exact letter, and applied a liberal Tung Oil coating, waited the hour or so and then wiped off all excess oil. Voila! It was magic, the coating hadn't bubbled or beaded and was satin smooth to the touch. I so enjoyed the result that I was getting I applied another 6 coatings to build up a deep and very beautiful satin (non gloss) finish that shows the pattern and features of the underlying wood grain. After my final coating and another week's hardening time, I gave my workpiece a final polish with some Snake Gully Beeswax and lots of elbow grease.

It was my first experience of using Tung oil and I now love the stuff for its nutty aroma and satin finish. But I learned it is long hard work that requires much patience, and above all that it gives a lousy bubbly beaded and sandpapery texture if the excess oil is not wiped off after the first hour or so. Could it be that your floor finisher is not at all experienced in the correct use of Tung Oil?

HTH,

Dado

Howdy,

Just wanted to get some advice on what to do with our new floor. We just had 100m2 of 130mm Spotted Gum sanded and finished with Tung Oil (not the pure stuff)... but it has reacted badly, causing a bubbling effect which looks like the floor was covered in dust when it dried.
The finisher says it isn't his problem if the wood reacts (SG being an oily timber). He HAS offered to dust back the the top coat to flatten out of the bumps and re-do the final layer. My question is- will this work? Or is it just going to happen again?
Also- the finish is WAY glossier than I was expecting - is it possible to get the finish looking more satin? Or is that just the nature of the hybrid Tung Oils?

Thanks

dado
5th September 2007, 06:47 PM
G'day again TOUCHDRY,

As an afterthought, I realised that wiping off excess oil from a free standing furniture piece is a much easier proposition, than being on hands & knees crawling over a large flooring area. I seem to recall reading somewhere about thinning Tung Oil 50/50 with mineral Turpentine to make it soak into the grain more deeply and aid drying, but cannot find that article presently. I'll keep looking, but in the meantime, the following might help a little.
Read on from URL:
http://www.woodart.com.au/a_intergrain03.htm

"...Tung Oil or "China Wood Oil" is a natural organic vegetable oil extracted from the nut of the Tung Tree, used by the Chinese for centuries to protect and
beautify timber and regarded as the ultimate oil finish for enhancing the natural beauty and grain of timber.

WHERE TO USE
On new or old bare or previously oiled interior woodwork, furniture, floors, doors, beams, panelling, carvings, turnings etc.

IMPORTANT POINTS:

list of 3 items
• Tung Oil penetrates and dries to a non tacky matt finish. Hand rubbing, buffing and waxing are required to produce a soft lustre.
• Tung Oil may darken certain timbers, test for suitability before use.
• Tung Oil does not produce the hardness or chemical resistance of modern synthetic coatings.
list end

SURFACE PREPARATION
Nail holes and surface defects should be filled with
Intergrain Woodblend
woodfiller.
Bare Woodwork Must be clean, dry and fine sanded with 320 grade or finer sandpaper.
Previously oiled woodwork: Must be free of wax, remove with synthetic steel wool and mineral turps if necessary.
Floors: Final sanding should be done with 320 grade sandpaper in the direction of the grain until a bare clean surface free of scratches is achieved.

APPLICATION
GENERAL:
The condition, age and species of timber will dictate the number of applications necessary to achieve the desired results.
Exposed beams and ceiling lining, 1 liberal application.
Hardwoods 2 or more applications
Soft, porous, old or recycled wood may require 4 or more applications.
Apply liberally by brush, soft cloth, mohair or lambswool applicator thoroughly saturating timber. Allow 1/2 hour for oil to absorb and buff to remove
surplus oil. Allow to dry and repeat as necessary until complete and even saturation of the timber is achieved. After final application allow 12 hours
drying before hand or machine buffing. Floors and Benchtops: Apply a heavy coat by brush or lambswool applicator and allow to dry overnight or longer in
cold conditions. Sand lightly when dry with 240-280 grade dri-lube paper, remove dust and apply second even coat and allow to dry.NOTE:Old or porous timbers
and softwoods may require additional coats to achieve an even finish. Sand after each coat with 240 grade dri-lube paper and remove dust. Apply a final
light finishing coat with a lint free cloth or lambswool applicator, rub in thoroughly and remove surplus oil. It is recommended that the undersides be
sealed to prevent warping.

LOW LUSTRE HAND RUBBED FINISH Apply oil to timber pre-sanded with 320 grade sandpaper or finer, rub in thoroughly along the grain with 000 steel wool or
400 grade wet and dry paper, leave for 1/2 hour then buff surface to remove surplus oil. Repeat as necessary until a silky smooth finish is achieved, allow
to dry and buff thoroughly to a soft uniform lustre.

WAX FINISHING A suitable wax finish such as the Feast Watson wax may be applied for additional sheen and protection.

TOUCHDRY
6th September 2007, 05:00 PM
Thanks guys for the detailed responses!

Dado- your description of 'rough sandpaper' is spot on, that's exactly how I would describe the problem. I'm almost certain that the polisher applied the coats a) too quickly and b) too thick. BTW he has also p..'d off the painter by not taking enough care around the skirting and leaving gouges along them. I think careless work is the cause here.

And to think the guy was 10 bucks a square metre more expensive than the competition- a fact we thought would help in getting a superior result. Guess we were too naive.

jaspr- I won't rule out the manufacturer issue. I will have to find out what brand it was.