I believe it is a chemical reaction between the bleach and the finishes. To quote Mr Hyatt: Do not use bleach ever!!!
Get the EFC 38 and Citralic from www.woodrichbrand.com, reclean, and then apply the woodrich stain. george@eastteak
John--chime in hear if I am off base on this

I agree it is probably some sort of chemical problem. I just got the Woodrich cleaners and I am planning that as my next step. Do you have experience with the Tux clear on mahogany? Is it really clear or is there some color to it? I am trying to keep it as natural as possible.

Thanks.

Tom

Tom,

I don't think John Hyatt has said "Never use bleach". He says, "Never use a power washer" because if used improperly it can damage your deck. Bleach is very effective on mildew and should not harm a deck if a mild solution is used. It is often less damaging to an existing finish compared to a percarbonate cleaner. Sodium Hydroxide strippers can turn a deck black which is why they have to be neutralized with an acid like oxalic or citric acid.

Your deck turning black is a mystery. The Grime Scene is a site for power washing professionals. They have a DIY forum where you can post photos and ask questions . They may be more familiar with your problem. http://www.thegrimescene.com/forums/forum.php

Marty

Thanks Marty. I took a quick look at the site and it looks like it may be very helpful. I am on the beach on Cape Cod without Internet access for the next week, so will pick this up them. I will start with recleaning a small area with the Woodrich products. I may have to be treated for withdrawal after a week without Internet access.

Thanks.

Tom

Never use a power washer or bleach on an outside project.

Using both woodrich products will cure most deck finish problems combined with the sprit of a sound mind. J.

I am back from vacation and finally got around to cleaning a portion of the deck with the Woodrich products, no power washer. I will wait a few days to be sure it is dry, then try the stain.

I just realized I never reported back on my problem. Cleaning the deck with the Woodrich products solved the problem. I am now a believer!

Sorry to awaken an old thread.

What finish did you end up using? I am putting in a mahogany deck and want something clear to preserve the color. Any suggestions?

Keep in Mind. >>> no clear or natural outdoor finish has uv protection Reread. Again.

Using them will let your decking go gray,left alone and it will darken, A Lot.

There is no " preserve the color " with wood laying flat to the sun it will not stay the same color Sooooo a finish with uv,mildew,water protection and Color must be put on.

Color = micro metal geting into the wood and refelcting the sun, the same way sun block works on your skin.

This is message 101. Total sending on this site ..9,000,226 and counting.

yeah i ended up putting on an Olympic clear with UV and it all flaked off. I think the wood was wet.

I loved the look of the clear on the Mahogany. John can you recommend a stain that will give a similar look? The clear really made each plank's uniqueness and color pop.

Any recommendations for a pigmented oil stain that mimics the look of clear mahogany?

spar marine varnish..no stain..
look for boat varnishes..just about any will work

forget using a stain(coloring)

just my 2 cents

-dkenny