What product to cut / polish this annoying staining away ?

[superheat6k]

I have cut the topdsides on Boadicea using 3M Fastcut. The majority of the topsides have come up really well right around the boat, except one area of the port quarter where the mop has touched the blue detail lines just above the waterline, and this has stained into the gel in an area ~ 2' square. I think I had the mop runnign a bit fast and the pad was gettign tired as this was the last section of the boat, but which time I thoroughly had the hang of it.

I have tried a further cut with Farecla G6, and then further cuts with the 3M Fastcut. The surface is lovely and shiny but has this light staining just visible.

I am thinking about giving the area a light rub with some wet and dry say 600 up to 1500 grit used wet, but is there another cutting paste I could try to cut this area back to remove the staining. I wil be using some phosphoric acid on the rust staining below the beaching leg fitting plate, although most of the staining has been shifted by the Fastcut.

Thanks.

 

[eilerts]

I have really no straight answer to your question. Smearing colour from such film strips is not uncommon, but I hav never experienced that the stains does not go away by light rubbing. It is strange that smearing would affect the gelcoat beyond the surface. Could it be that you have uncovered an old repair with under-cured or highly porous gelcoat? Under-cured gelcoat get sticky when rubbed and may accept colored contaminants.
You may try wet sanding, but I would start at 1000 grit. Start with masking the blue stripes. Test if it solves the problem on a small part.

 

[RichardS]

I would use Peek but I think that is probably very similar to G6 so if that doesn't shift it I don't think that it will be removable.

Are you sure that it is not an old repair which is just showing through?

Richard

 

[Aquaboy]

I would try a little bleach, just a test area and be ready to rinse away just in case. May work

 

[Refueler]

Bluebell or Brasso metal cleaner ........ then a good dose of T-Cut and polish to get shine back again.

 

[boatmike]

You may have burned the gel coat by running too fast and or lingering too long over one area.If you raise the temperature of the gel coat it becomes fluid and you can stain it with pigment from the blue for quite a depth. Try rubbing back with wet/dry but if this does not work I am afraid the only cure is cutting right back and filling with new gel coat. Hopefully this won't be necessary.

 

[pvb]

This is one reason I polish by hand!

 

[boatmike]

This is one reason I polish by hand!

Hand polishing is fine to clean and apply new wax if your gel coat is in good nick. If you need to cut back resurface and polish old gel coat though you need a machine. You do need to practice the art though and avoid overheating the surface. Easy with a good machine and the right product. Not easy if you use stuff designed for automotive use like Ferecla G7. This only works at fairly low RPM. Ferecla Select is what you need for GRP and is great up to 3000 RPM with relatively light pressure and a lambswool mop. Try it once and you will never use anything else! Oh and please don't put bleach on gel coat. Polyester does not like bleach at all!

 

[pvb]

Hand polishing is fine to clean and apply new wax if your gel coat is in good nick. If you need to cut back resurface and polish old gel coat though you need a machine.

I used to hand polish my 24 year old gelcoat on the previous boat.

 

[James_Calvert]

Just in case no-one offers the same thought...

It's blue.

Blue fades.

You could try just leaving it, before attempting anything drastic.

 

[Elessar]

You may have burned the gel coat by running too fast and or lingering too long over one area.If you raise the temperature of the gel coat it becomes fluid and you can stain it with pigment from the blue for quite a depth. Try rubbing back with wet/dry but if this does not work I am afraid the only cure is cutting right back and filling with new gel coat. Hopefully this won't be necessary.

Unfortunately I think you are 100% correct.

 

[Elessar]

This is one reason I polish by hand!

Some modern polishes only work by machine. They start course and break down to a finer polish as you work them.
As long as you never let the machine stand still it is quite hard to cause a burn. But you have to Ben careful in corners particularly internal ones.
And the machine saves days of work.

 

[ghostlymoron]

There was a car polisher in the Special Buys bin at Aldi the other day.

 

[pvb]

Some modern polishes only work by machine. They start course and break down to a finer polish as you work them.
As long as you never let the machine stand still it is quite hard to cause a burn. But you have to Ben careful in corners particularly internal ones.
And the machine saves days of work.

Understand that some polishes need machine application. But the Meguiars polish and wax I use are the least effort I've ever found. I can do 2 coats of polish and 2 coats of wax on my hull by hand in a day and a half.

 

[Ian_Edwards]

I bought a Meguiars about 8 years ago, I viewed it as an investment, there's a lot of topside to polish on a 46 ft boat. It takes me about 2days to polish and wax the hull.
I use Meguiars all in one polish and I've found over the years that it's better to apply the polish by hand and then polish it off with a yellow fine foam pad. I wax by hand.
The Meguiars is relative light and easy to use, I'm 73 and I still manage to wax and polish the boat myself.
I've always worked on the assumption of buy cheap, buy twice.

 

[tjbrace]

Cillit Bang shifted the bird poo stain in seconds after pressure washing off the turds.

 

[LadyInBed]

Are you sure that it is not an old repair which is just showing through?

Judging from its position, it looks like fender stain to me.
I would give it a go over with Cif then use your favorite brand of polish.

 

[superheat6k]

I think this was me getting a bit gung ho after I had successfully cut back some 7/8 of the topsides with the mop (a Sealey) running at setting 2. I then wound the speed up to 4 and caught the blue line, so likely a brief overheat as a result of me overdoing it.

It is one of those stains that doesn't show much beyond 2m and is invisible at 3m away so I am going to try gently hand buffing with some 1500 and at worse 1000 grit wet & dry used wet. If this doesn't improve it then I will simply cut it back again with the 3M Fast Cut or Farecla G6 to a decent shine and then find something else to worry about.

The wax won't be going on until the Hempel Silic One system has been applied. I don't want any wax splashes on the antifoul surface that will stop the Silic adhering.

 

[superheat6k]

Went back to the boat today and lightly rubbed the area with 1500 grit wet & dry used wet. Interestingly a good deal of the staining has faded back considerably, and after about 10 minutes gentle honing the surface, I wiped away the residues and ran the mop over again at a low speed with the 3M fastcut.

The shine has fully restored, and yes if you look really close at 1m distance the blue tinge is still just visible, but 2m away nothing stands out. I can live with that.

Thanks for the advice.