The Rot Doctor


Subject: CPES (cleanup on teak)
Date: Wed, 14 Jan 2004

Dr. Rot.

I have a 1973 38' Chris Craft Coho Aft cabin with a lot of teak on the deck. For 15 years it sat under shed, bow to the weather. Over time the seam caulk wore away in a few places allowing water to enter and de-laminated a lot of plywood. The anchor locker is the worst but the shear shelf is good shape. I removed the headliner from the vee birth only to find a lot of soft plywood. The last thing I wanted to do was to remove the teak and replace the plywood. So I removed all of the caulk using a Feinmaster with a caulk blade that also cut up and removed the oakum, This was quite easy. I then took a 3" 12 volt circular saw and cut just a bit into the plywood to give CPES some run through room.

I bought 2 gallons (I will need some more soon). In quite a few places about 5" by 5" I injected over 16 ounces of CPES and found that it had run through by the next morning. Overall, it has done the job but it's quite tedious and slow going. However, I got a lot of CPES directly on the teak deck through various ways including over pooling CPES and drips. On one occasion I got a leg cramp and kicked over about 12 ounces onto the deck. This certainly filled a lot of seams nicely but, as you now guess, left a big CPES stain on a large portion of the deck. I tried to wipe it up with paint thinner but there are still unpleasant stains on the deck.

So, when I finish my work on the foredeck teak is there a way to get rid of the stains? Perhaps by sanding? Perhaps by heating it first then sanding? Or, should I just sand the best I can then pour Cetol all over the deck, which is not what I wanted to do in the first place. Any ideas you have WILL certainly be appreciated,

Joe G.

On good wood, especially dense hardwoods like teak, CPES does not penetrate all that far. Try just sanding the surface. Don't heat the wood as that tends to make the CPES gummy which will load up the sandpaper. You might need to take off a millimeter or two at the most, but I think that you will be satisfied with that. I would expect that after sanding, the teak should look like new wood with no evidence of the CPES. There might still be some CPES in the open pores of the wood, but not enough to notice without a microscope. Any CPES that got into the sides of the seams I would just leave. It will help the adhesion of the new caulking material.

Come back if you have more questions.