Black Marks

[chrisg]

Hi all

Anyone got any clever tips for removing black rubber "grazes" from fibreglass. Over time a few oyster poles and posts have left their mark. A cutting polish doesn't do much nor WD40 which was the last tip I got.

Any ideas?

C.

[defyet]

Hi all

Anyone got any clever tips for removing black rubber "grazes" from fibreglass. Over time a few oyster poles and posts have left their mark. A cutting polish doesn't do much nor WD40 which was the last tip I got.

Any ideas?

C.

Hey Chris,

Im a detailer so i have come across all types of problems, is the black mark transferred from the pole, or is it an actual scrap on the paint? Polishing by hand wont do much even with cutting compound, gelcoat is tough so it would be best to use a machine polish to remove any marks.

Chemicals wont do much to remove it unless it breaks the rubber down which wont happen. If that fails then you can get whats called a Caramel Wheel on the end of a drill which is used to remove sign writing but be careful not to ruin the paint.

A picture would be helpful though so i can see exactly what it looks like

[chrisg]

Now I've looked closer it looks like tar. Some oysters posts are painted with a tar paint for protection. I've got the residue off but the remainder seems like a deep stain in the gel coat.

Out of interest I tried a marine extra cut compound in an inconspicuous spot, Good job I did cos now I have a heavily scratched matt finish spot that I cannot get a gloss on regardless of what I do. Tub says it will produce a high gloss finish. Just used small circular motion by hand..what went wrong?

C.

[whi7eindustries]

Now I've looked closer it looks like tar. Some oysters posts are painted with a tar paint for protection. I've got the residue off but the remainder seems like a deep stain in the gel coat.

Out of interest I tried a marine extra cut compound in an inconspicuous spot, Good job I did cos now I have a heavily scratched matt finish spot that I cannot get a gloss on regardless of what I do. Tub says it will produce a high gloss finish. Just used small circular motion by hand..what went wrong?

C.

Hey mate, give sugar soap a go, gets all the nasty stuff off the side of my Bertie where the bilge pumps out, can't be any worse than that stuff.

Cheers, Tobe

[defyet]

Have you used Thinners or a white spirit? thats what is commonly used to remove tar, or an acid cleaner will remove it with some rubbing, hydrochloric or hydrofloric. As for where you can get it from im not sure cause i buy in bulk from a supplier so thinners would be the best option, it will be tough to remove so expect it to take some time.

Its still a bit hard to give the right advice without seeing it though, you caused the blemish in the gelcoat because the compound was too harsh and too much rubbing, chances are you only hazed the gelcoat so it can be fixed. Were you using a rag? You should really use a foam applicator pad as rags/towels are way too harsh especially with a compound.

The problem with polishing to remove marks like that is that you end up polishing to much around the actual mark and damaging the paint before the mark even thinks of coming off. The best course of action is chemical cleaning to remove it like thinners and scrubbing it, then remove any fine scratches with the compound/polish.

Paint transfers or marks transferred from another surface are always harder to remove then scratches or scuffs.

[chrisg]

Yeah used a soft cloth and hazed is a good description. How should I best deal with that?

C.

[defyet]

Try using a foam applicator pad, you can get them from super cheap (Meguiars), and use light circular motions with the compound but fast. If its still causing problems then you will need a less abrassive polish.

[pjbink]

The only way I have found is to sand the mark out with 1200 grade wet and dry sandpaper (used wet).

[chrisg]

Thanks mate..actually got rid of the bulk of the marks using mothers old favourite...bicarb soda paste...cleans really well without scratching. Now to just get the gloss back!

C.

[rickb]

Thanks mate..actually got rid of the bulk of the marks using mothers old favourite...bicarb soda paste...cleans really well without scratching. Now to just get the gloss back!

C.

Hi Chris,

I use the same as Tobe,good old sugar soap,cleans,tar,rubber,blanket weed

gum stains from trees,then I buff it with 3M fibreglass restorer and wax,

comes up just like new.

cheers Rick.