Latest News: Forums Technical Removing old silicon under the rear locker hatch rubber

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    Anyone got any magic tricks (tools) for lifting off old silicon?…….or is it just scratching and picking and scraping away with sharp objects…the silicon is in a nice (not) deep bed all the way round and it is not possible to get a paint scrapper on it as its not a flat surface…..I suppose new stanley knife blades and keeping at it……..I was wondering about chemicals?


    I think the DIY stores now have sealant removers (normally on the same shelves as sealants) – but I’m not sure about Gel Coat stability – so you’d have to do a small test first.



    With all of the repairs that I have carried out on W3035 Acetone always seemed to do the job on all types of glues and mastics. It’s relatively cheap if you get a large container 2.5 litres from fibreglass suppliers. It certainly cleaned everything of the fibreglass hull with no problem at all.



    Finally finally finally …… rid of the old silicon. Could not get a flat blade onto it because the silicon lay in a gutter finger thickness. With much general gouging and scraping I got rid of 90% of the volume. Using plenty of acetone still did not seem too effective, however in retrospect it might have been softening it a bit for more scraping. (Porters recommended acetone for cleaning before fibre glass jobs when I called them a couple of years ago).
    Looking for silicon sealant remover in DIY stores…….B&Q no joy, nor Wickes….finally found some in a marine chandlers although the packaging makes no reference to boat uses for the product……..made by “GEOCEL”…..(a strategic partner of Dow Corning it says on the box….interestingly it was past its use by date and was their last one so whether it is still made I don’t know. Cost £3.50. Anyhow its a gel that you leave on for two hours. This did the trick but still required more scraping…….this time with finger nails (so it was not a miracle cure). Finger nails now suspiciously clean but so is boat where silicon was………probably could have glued hatch seal over the traces of old silicon anyhow but proper job! Thanks for your help David and Peter.


    related to this how is the aft hatch/ locker/ bouyancy tank on a wood boat sealed? My boat, an elderly exmaple from 1964, came with two perished lengths of shock cord tied to a couple of stainless hoops and tied down through a hole drilled in the spine of the hull. useless; So I used some claw fasteners on the front but what about the back? I screwed a piece of timber to the underside of the lip of the cover so that it grips under the hatch opening; less than ideal. I sealed with expanding foam seal which would be ok but I’m now going to have to rebuild the wooden hatch cover anyway as the ply has split so I want to do an effective and watertight job. I’d be grateful if someone could send me ideas or photos of how they achieve a decent watertight seal.

    many thanks

    Graham Smout W918 💡

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