Oil soaked bottom planks

After two days of sanding the bottom clean, I came across an area where the paint came off easier that the rest of the bottom. I have two planks oil soaked. I am working with some asatone to see if I can get most of the oil out. Anyone have any input or experiance on this issue.
Manny

 

Tide detergent, repeatedly, until it's clean. Acetone will not do much, except draw out the moisture and thin the oil, making it harder to get out.

 

Detergent helps. Even though some oil will always be left, it may be enough to help paint adhesion. The problem with planks soaked in oil is that they won't swell and take on, so the seams will stay loose and leak.

 

The usual solution is replacement, which isn't unreasonable considering planking has a defined life span. Garboards, typically under engines are the first places to receive scarfed repairs or wholesale replacement.

 

Acetone will not thin oil.

I would try a heat gun on the wood to warm (and thin) the oil, and soak in carburetor cleaner (from the autoparts store). Wipe it off with a white paper towel, repeat until paper towel comes away clean. This should draw out most of the oil, than scrub with detergent and water to get the carb cleaner residue out. Once dry the paint should stick fine.

 

I've found heating the planks also makes things worse, not better, driving the oil deeper. You have a couple of choices, leach it out or float it out. Vacuum might work, though it would be a very slow process. I've seen anticoagulant (Tide laundry detergent) and water do the best and fastest job. Tide is what NASCAR uses on an oil strewn track after an accident. I've used it for years as a general degreaser and in powdered form, will also help leach out oil in planking. If really badly soaked, it's usually more economical (assuming you're paying for labor) to replace the soaked portion.

 

Copper bottom it.

 

The best bet is to replace the planks, diesel fuel leaches out the lignin that holds the fibers together, no amount of cleaning is going to fix this. I had this situation on the bottom of a customers Grand Banks 42 years ago where a steel fuel tank had been leaking for years, i had to remove a bunch of planks an cut a couple of frames to remove and replace the tank through the bottom and the wood had not much cross grain strength left when compared to the part of the same plank that wasnt soaked.

Steve.

 

I wonder why they invented creosote and why do they soak wood railway sleepers in oil. I know its to keep them in good condition and it would seem strange to soak in oil if it weakened them as its job is a load bearing support.

 

I am not remembering what the product is but....

Gunsmiths use a powdered clay which is heaped on oil soaked wood then a solvent is poured over.
The oil is draw up into the powder out of the wood. It apparently works quite well though I have not done it.

Par has it- damaged plank- replace.

 

Frosty, i would guess its somewhat species specific, i doubt oil would damage teak planking, but on the GB i worked on it looked like one of the many mahogany species and was soaked all the way through and if you cut strips off across the plank say 6" wide you could easily break it by hand whereas not so with a piece off the other end of the same plank, the long grain fibers were still tough and stringy, just nothing much holding them together. There was a 40ft Post sportfisherman at the marina next door a few years ago that had oil soaked planking that they cut up with a chainsaw because it was sitting in an oil slick, it was going to cost too much to replace the planks and they tried selling it but ended up getting a decent offer for the engines. Too bad, it was by far the prettiest powerboat in the area.

Steve.

 

It would not have been impossible for the plank to have been rotten before the leak.

 

Petroleum based oil will generally preserve wood since it kills micro organisms that eat wood. Hence the reason railroad ties and telephone poles are soaked in creosote, both have very critical load bearing functions, as frosty points out, and I know from my work that the industry standard is that wood preservatives do not affect rated strength.

Weakening it by softening the lignan is a different issue, and that might vary depending on species, thought both railroad ties and telephone poles are made from a number of different species, both hardwood and soft wood.

Consider that many of the older railroad bridges still in use today are creosote treated timbers. These are usually tressel designs (essentially a timber truss) and carry heavy loads, and it is exposed to the weather and wood eating organisms. There are a number around here that are close to a century old. Perhaps the heavy oil and creosote does not affect the strength as much as something lightweight like gasoline or alcohol.

 

Here there is a strong local tradition of wooden boats

(see my friend Kevin's photos for example: http://www.facebook.com/KevinOFarrellPhotographer some featured in an up-comming woodenboat issue)

The advice you would get in the best known wood boat yard locally to preserve a timber hull or spar would be to saturate it with a 50/50 mixture of parafin and boiled linseed oil. Hull planking would generally be Larch.

 

The planks were not rotten, just no lignen to hold it together in the oil soaked area. Perhaps the reason why creasote does not cause this problem is because it is not a petroleum product but rather derived from coal tar. I have no idea why the diesel leached out the lignen on the GB planking, just that it did, as i said before, it probably reacts differently with different woods.

Steve.