boats and silicon

[Jeremy]

Any tips on how to remove old silicone easily (eg. from behind moiunting board on transom)?

Also, what is the recommended silicone to use for redoing bungs and other fittings on a fibreglass hull? I am guessing sikaflex, but aren't there several varieties?

All tips welcome. Thanks.

Jeremy

[oldboot]

Silicon is a major pain to remove.

you realy have to scrape it off.

I have had very good results with a sharp ( I mean sharp) chisel.
start with a wide sharp ( did I say sharp) chisel bevel down on the surface.

woth care you should be able to slice the bulk of the silcon off the surface without damaging the base material..... sharpen that chisel and keep the bevel flat on the surface.
follow that with some for of properly sharpened scraper.

It realy depends on how much silicon you want to get off and what you want to put over it.

If you are going silicon again you don't need to be too fussy.

Sicaflex isnt a silicon...... generlay the grades we talk about it is a polyeurathane sealer..... and is all over silicon like a rash.

There are other polyeurathane sealers out there but sicaflex is king.

cheers

[fiftyfifty]

Jeremy,

Have a look at http://www.sika.com.au/cmi/marine_products.htm

This has information about Sikaflex 291 Marine grade adhesive/sealer. This will do the job for you. It cleans up (before curing) with turps.

[Mark-P]

Jeremy.. Neither of these products will stick succesfully to plastic !
They form more of a oring type of seal when it come to bungs !
Sikaflex dosn't stick to painted or polished surfaces as well as
non acidic silicone either ..... But if you use sika primer 1st, the
Sikaflex seems to hold better !!
Another good remover of silicone is steel wool.. Once you remove
the bulk of it use the wool with some turps....

Mark

[Jeremy]

thanks for the replies. Just cleaning up the transom by removing and resealing the bungs, old outboards is off waiting for new and I have now removed the old backing board which left alot of silicone behind. Also removed a strip of alluminium trim where the transom meets the outboard well. Needed a bit of a clean and reseal.

Jeremy