cleaning boat bottom/heavily stained

rocky111 · 11-10-2008, 02:14 PM

hi folks anyone got any suggestions as to what i can clean the bottom of my boat,the stain is very heavy almost black in places i have already tried TFR,and household bleaches but no joy,The boat has only ever been kept in fresh water and is original gelcoat.

Silversurfer · 11-10-2008, 02:22 PM

brick cleaner or brick acid from B&Q just paint on with a brush wear gloves protect galvernised trailer i wear eye protection as well. leave on for a couple of mins and hose off with plenty of water. Job done in 10mins max. Once dry rewax hull.

Hydrostream · 13-10-2008, 01:15 AM

Alloy wheel cleaner, spray it on and wash off with water

Jon Fuller · 13-10-2008, 11:18 AM

I don't like all those aggressive cleaners, with acid etc.

Just about any stain will come off easily with some elbow grease and T-cut. it also removes a minute layer of outer gel, and leaves a smooth finish that will resist future staining, especially if you wax it after polishing, whereas the aggressive stuff will leave a perfect keyed finish for the staining to return, ie, it's a short term fix.

JMHO.

Hydrostream · 13-10-2008, 07:33 PM

Quote:

Originally Posted by Jon Fuller

I don't like all those aggressive cleaners, with acid etc.

Just about any stain will come off easily with some elbow grease and T-cut. it also removes a minute layer of outer gel, and leaves a smooth finish that will resist future staining, especially if you wax it after polishing, whereas the aggressive stuff will leave a perfect keyed finish for the staining to return, ie, it's a short term fix.

JMHO.

Agreed, but for a one time deal it should be ok!
I have often wondered about the use of chems on gelcoat, most if not all gelcoat now is isophthalic and should resist a mild exposure to chemicals for a short period of time.
Whereas polishing and repolishing gel opens up porosity, a great place for dirt to lodge.

Jon Fuller · 13-10-2008, 07:39 PM

I certainly agree that you can't beat a nice, original virgin mould finish. That seems to be the most resiliant to all stains etc, and has a real nice lustre (assuming the mould finish is good) but this guy sounds to be way past the original lustre stage.

don't like acid.

Pash 1 · 13-10-2008, 07:41 PM

Quote:

Originally Posted by Jon Fuller

I certainly agree that you can't beat a nice, original virgin mould finish. That seems to be the most resiliant to all stains etc, and has a real nice lustre (assuming the mould finish is good) but this guy sounds to be way past the original lustre stage.

don't like acid.

Cilit Bang ? Works on engine bays might be worth a try

chris · 13-10-2008, 10:33 PM

starbrite hull cleaner is very good , acid is not ,what happens is when the boat returns to the water it will go a browny tint very quickly , then the only thing to shift that is more acid which cant be right.

Hydrostream · 13-10-2008, 11:08 PM

Starbrite hull cleaner is acid based, it is actually alloy wheel cleaner, that's why I sugested it as it's half the price, same stuff!

Cilit bang works well too, but again, acid based...

rocky111 · 13-10-2008, 11:12 PM

thanks guys,over the weekend i tried an acid type cleaner on a small area and it was brilliant ,came off with ease,but after what john mentioned about the chemicals im not sure about doing the entire boat with it,what if i were to machine compound and wax afterwards,any thoughts.

chris · 13-10-2008, 11:18 PM

what about viakal tap cleaner is that acid

rocky111 · 13-10-2008, 11:29 PM

No idea ,i have never heard of it,but im definately having second thoughts about using the acid,whilst it removes the heavy stains easily,i dont want to leave myself in the situation where it gets stained quickly when launched again,then more acid

weehenry · 14-10-2008, 12:26 AM

try y10 brush on wash off

Hydrostream · 14-10-2008, 01:09 AM

Quote:

Originally Posted by chris

what about viakal tap cleaner is that acid

it's probably limescale remover, which is probably a mild acid solution, Y10 is an acid for sure!

My curiosity has always been that, compounding removes a layer and exposes porosity in the gel, chemicals dont remove this layer but certain chemicals can break down the molecular structure of the gelcoat! Most gel is now Isophthalic which has a higher resistance to chemical exposure.

Some fuel tanks are made from fiberglass and have a constant exposure to chemicals.

Quote:

Isophthalic: Reacted into the resin, isophthalic acid provides greater levels of water (acid) and chemical resistance than does orthophthalic anhydride. This is especially important in the manufacture of boats, shower and bath enclosures. Greater chemical, weather and corrosion resistance with a higher degree of flexibility are the immediate benefits when isophthalic acid replaces orthophthalic acid in the resin.

I've seen some water stains in gel so deep that even compounding wont remove without a 600 heavy cut!
So it's just a matter of which is the lesser of the two evils.

Dont leave your boat in the water very long

weehenry · 14-10-2008, 01:21 AM

i bought a bottle of wax for under the hull a couple of years ago it was supposed to help performance and keep the hull fron staining it was called safe speed skin i took the boat of the trailer and applied five coats as instructed
i put the boat back in the water and after three days i noticed it stained and after the season the boat was as black as the ace of spades
the polish stayed on ok but instead it stained and was a night mare to get off

and it cost me 80 quid

Jon Fuller · 14-10-2008, 08:09 AM

Quote:

Originally Posted by Hydrostream

Dont leave your boat in the water very long

The best advice so far, by far.

Dry berthing rules.

Shelbysteve · 14-10-2008, 08:32 AM

Stick a picture of the stained hull on here so all can see! Gosh TFR normally removes everything. The boat must of been moored right outside a curry house!

If Y10 doesnt remove it either, You may need to try something as old fashioned as T-Cut or 3m hand glaze and elbow grease.

Never used this but i found this on a site http://www.marinemegastore.com/produ...t_id=MAICLE002

weehenry · 14-10-2008, 11:32 AM

try a few lbs of semtex hat ill defenetly shift it lol

red 5 · 14-10-2008, 08:35 PM

Quote:

Originally Posted by Silversurfer

brick cleaner or brick acid from B&Q just paint on with a brush wear gloves protect galvernised trailer i wear eye protection as well. leave on for a couple of mins and hose off with plenty of water. Job done in 10mins max. Once dry rewax hull.

YES BRICK ACID it doesn't damage the hull. Spray on with ( weed killer sprayer type thing) leave for 10 mins and wash of with water. TAKE CARE and don't get is close to any metals ie engine, rails etc....

rocky111 · 14-10-2008, 10:49 PM

where will i buy such a thing or is their a specific type to ask for,thanks.