silicone grease and gelcoat

[Dignity]

I was using silicone liquid grease, it's used for lubricating cables in pipes etc, and after using it the rag I used to wipe off the excess I unthinkingly left on top of the boat while I accepted a parcel and some remained on the gelcoat. Now I wiped off the silicone and interestingly the gloss and colour came up better than ever. Now somewhere in my dim memory banks I recall that silicone was bad news for gel coat, anyone any experience or knowledge about this.

[tug_tellum]

Hi Dignity, when manufacturing fibreglass products you cant use silicone based wax on moulds as the gelcoat wont sit on it. You will create fish eyes. Is this what you were thinking about?
Tug Tellum

[Dignity]

Tug,it's quite possible what remains in the vestiges of my memory. There seems to be a lot on the net about removing silicone sealers from gelcoat, from what I understand the silicone gets right into the gelcoat and you virtually have to grind it back. I've tried cleaning the silicone off where the rag sat but the area is still deeper in colour and remains relatively glossy. Its also confusing when you read labels of certain polishes and waxes that state either they contain silicon (and PTFE) or they are silicone free. I just don't know what effect direct sunlight will have on it.

[tug_tellum]

If you look at gelcoat under a microscope You will see the porosity (some times you can see it with out a microscope or magnifying glass if its really bad) These porosity holes will hold silicone or wax or anything that you spill on the gelcoat. As you say most of what you read on the net is about removing silicone that was used to seal something like windows/fittings etc. Grinding will get rid of most of it but probably not all. I dont know of what effect sunlight/uv has on the silicone that you used. I would imagine that the silicone would break down eventually,hopefully before you need to do a gelcoat repair.The waxes we use in manufacturing are Carnuba based waxes and these dont contain silicone. We also use a sealer resealer glaze on moulds to try to fill porosity in tooling gelcoat prior to application of coats of wax.. This material also has a light cutting compound
Hope this helps. I dont profess to know it all .
tug tellum

[scottar]

Don't know about gelcoat but I do know that panelbeaters love touching up cars that are silicone wax polished............not. I think there is a paint additive that will allow it to stick but without it I think it just runs.

[Dignity]

Thanks Scott, I suspect it's as tug-tellum says the gelcoat is porous, I guess I'll just have to polish and wax the rest to match, just hoping it sits there inert and does nothing.

[Dignity]

If you look at gelcoat under a microscope You will see the porosity (some times you can see it with out a microscope or magnifying glass if its really bad) These porosity holes will hold silicone or wax or anything that you spill on the gelcoat. As you say most of what you read on the net is about removing silicone that was used to seal something like windows/fittings etc. Grinding will get rid of most of it but probably not all. I dont know of what effect sunlight/uv has on the silicone that you used. I would imagine that the silicone would break down eventually,hopefully before you need to do a gelcoat repair.The waxes we use in manufacturing are Carnuba based waxes and these dont contain silicone. We also use a sealer resealer glaze on moulds to try to fill porosity in tooling gelcoat prior to application of coats of wax.. This material also has a light cutting compound
Hope this helps. I dont profess to know it all .
tug tellum

Do you use a particular brand of carnauba wax, I've been trying to get hold of some Collinite as it was quite good when I had some once before but a bit hard to get locally.

[ranmar850]

When I asked for a recommendation for a polish to seal my brand new fibreglass boat, the shipwright told me to look for a high silicone polish. Make of that what you will.

[Dignity]

When I asked for a recommendation for a polish to seal my brand new fibreglass boat, the shipwright told me to look for a high silicone polish. Make of that what you will.

Ranmar I would have thought you only need a good wax not polish for a new boat. Surprisingly Mason Marine Trimming in WA sell Collinite at quite a reasonable price, if I can't get some here I'll be getting some sent from there in O'Conner.

[juggernaut]

The Starbrite premium polish and cleaner wax from Whitworths contain PTEF. They are also petroleum based vs water based such as Dulon

Ive also used the Starbrite polish on my black car. Shine is amazing and water beads beautifully. Although I have my boat professionally polished with the Dulon component system.

[Noelm]

I wonder if acetone will clean it off?

[Andy56]

I wonder if acetone will clean it off?

i think it will but i would try putting some silicon grease on some timber first to try. I certainly wouldnt leave it on more than what t takes to get the grease off. On the other hand, if it leaves a nice shine, maybe cover the whole boat with it, lol.

[shakey55]

Try sending the manufacturers an email outlining your concerns. They may have the answer as I would think they may have come across this in research and development.

Can’t hurt


Sent from my iPhone using Ausfish forums

[Dignity]

Both turps and acetone cleans if off the surface but the problem is a slightly porous surface. I'll go over it with some wax once I've rubbed enough to try and remote it.
I've put it on a number of surfaces to see if I can get it out as per Andy56 suggestion and found one interesting item, I have some old coaming rubber which I've kept (I know a hoarder but it's in a pile of stuff ready to go) and I was surprised to find that if I rubbed it in it gave the rubber a new shiny look which is interesting as I've tried many different ways to restore it in the past. On application it felt like it was cutting through the previous crap, it only takes very little silicone and does leave a slightly almost sticky touch but I might try the power buff it to see how it goes. Maybe it needs another compound to finish it off. I did recently see a 500ml jar of something similar for sale at $82 but don't recall where.

[Funchy]

You haven't ruined my boat have you Sam?

[tug_tellum]

Do you use a particular brand of carnauba wax, I've been trying to get hold of some Collinite as it was quite good when I had some once before but a bit hard to get locally.
Hi Dignity
If you go to any fibreglass supplier they will sell mould wax which is what you want. There is no cutting compound in mould release wax. Your local fibreglass factory may sell you some if you ask nicely.
Noelm, I havent found acetone or anything else gets rid of silicone. It does dilute it but like a Horrible Dreaded Pox nothing gets rid of it :)
tug tellum

[Dignity]

You haven't ruined my boat have you Sam?

Just trying to make it pretty for you Luke.


Try sending the manufacturers an email outlining your concerns. They may have the answer as I would think they may have come across this in research and development.

Can’t hurt


Label lost long time ago unfortunately. It originally was packed as part of a cable joint package, found it very usefully for getting cable through pipes etc and only need a very small amount so it has lasted forever, a citron based cleaner from switzerland was used to clean up excess but don't have any and the stuff you buy these days is useless.

[DATCOL]

Hi Sam i would start with degreaser & then wipe down with thinners finely give it a polish

[Dignity]

Thanks COL, to be truthful it's not a large stain abut half the sise of my palm, wax job coming up next week and hopefully if it decides to change its small enough to not really be noticeable.

[tug_tellum]

Dignity, if left alone it will probably wear off sooner or later. I dont know of any harm it will do.
tug tellum