Topic: Cleaning black spots off roof

peaenjay    -- Oct-16-2021 @ 4:13 PM
  My Alpha 32 has a lot of black spots on the roof that are very difficult to remove even with a pressure washer. Advice on how to remove them gratefully received

Captain-Joshie    -- Oct-16-2021 @ 6:01 PM

Try a cleaner from Hugh Crane in Acle called Ubik 2000.

I used to get similar spotting on Braveheart, a 10:1 strong mix and the use of a softish nail or scrubbing brush did the trick ever time, you don’t need to put pressure on the brush just enough to work it into the grain texture. If you’ve got some stubborn spot use it neat. For general cleaning on the boat or at home dilute to 100:1, it’s great stuff and even food safe!.


Kind regards, John(Captain
Joshie) , Jo & Ivy the new dog ??.

Dodger65    -- Oct-16-2021 @ 7:08 PM
  I would also recommend ubik 2000
Used to use it on my boat
Just given my greenhouse a complete clean with it
It is magic and goes a long way

Keep That Boating Smile

This message was edited by Dodger65 on Oct-16-21 @ 8:08 PM

peaenjay    -- Oct-17-2021 @ 1:45 PM
  Thank you both for the advice, I will stop by this week and buy some.

Stingers    -- Oct-17-2021 @ 4:07 PM
  These spots look very much like the grey or black spots of mold which were discussed on this forum about 2 or 3 years ago. Of the suggestions offered, I found that Milton fluid or an equivalent applied neat to the spots and left for 2 hours worked very well and prevented recurrence. Besides penetrating to kill the 'roots' it also softens the growth enabling removal with a stiff brush or pressure washer. I would start with the larger spots first to test its effectiveness before moving onto the smaller spots.
I hope that helps.


spiderman    -- Oct-17-2021 @ 5:16 PM
  Go easy with the Ubik. I sprayed a dilution of that on the hull of my boat just before it lashed with rain, I sheltered from it for half an hour or so to then find it had left streaks that I haven't been able to blend in as yet. Hopefully a proper clean and a light compound will do the trick.

Greybeard    -- Oct-17-2021 @ 7:41 PM
  The surface appears to be severely micro cracked,, and is providing a good medium for moss,moulds and other similar organisms.
If it is a localised area it might prevent growth by a suitable coating of some kind.
treatments may be short lived as dust and dirt will soon fill those micro cracks providing ideal conditions for regrowth.

my appearance is down to me, my attitude is down to you.

pirate    -- Oct-18-2021 @ 9:49 AM
  We have same on our Alpha and use Astonish mould remover works fine with nail brush for stubburn areas.


Captain-Joshie    -- Oct-18-2021 @ 12:01 PM

Looking at the photo it looks like it is a anti slip surface either on deck or roof,  on Braveheart these where moulded in when made. Being fairly flat did not drain well allowing mould to flourish, I clean it 2 or 3 times a year depending how bad a season it was for cultivating moulds and algae.

I used to simple spray on a 10:1 mix, very lightly rub in to the ‘grain’ effect, and rinse off with clean water. Job done for a few months at least and a gleaming pure white surface. See photo.

The hull never got Ubik 2000 on it, it was dark blue and did suffer with hard water streaking. Only ever cleaned it with Hugh Crane Trans Wash which is what the BA Rangers use on their launches.


Kind regards, John(Captain
Joshie) , Jo & Ivy the new dog ??.

warrior    -- Oct-19-2021 @ 11:08 AM
  Have you tried Pink Stuff?  Buy online, Liquid or paste,  its brilliant and not expensive.
Cheers  Smile


peaenjay    -- Oct-20-2021 @ 12:50 PM
  Thanks for all the proposals, hopefully these will do the job.

The Norfolk Broads Forum :