Gelshield 200 Advice for using

[clonlara]

Hi folks, I have just finished scrapeing off all the old antifoul and am looking for any advice,tips or hints as to where to go next . The hull is very clean with just a hint of antifoul still visible. Does this require further sanding? After applying the epoxy coats does it require primer before antifouling and how long should it be left before antifouling? Finally a silly question. Do you use masking tape on the waterline and if you do when do you remove it bearing in mind that if the epoxy goes hard on top of it, it will never come off. Any advice etc. would be very welcome.
Colin

 

[Playtime]

Hi folks, I have just finished scrapeing off all the old antifoul and am looking for any advice,tips or hints as to where to go next . The hull is very clean with just a hint of antifoul still visible. Does this require further sanding? After applying the epoxy coats does it require primer before antifouling and how long should it be left before antifouling? Finally a silly question. Do you use masking tape on the waterline and if you do when do you remove it bearing in mind that if the epoxy goes hard on top of it, it will never come off. Any advice etc. would be very welcome.
Colin

All traces of antifoul should be removed - use an orbital (or 'mouse') sander to remove the last traces.

The antifoul can be applied direct to the final coat of epoxy, provided it is within 24 hours or so (see the datasheet).

Use the blue 3M masking tape not the cheaper tan coloured stuff. It is much tougher. However, it should still be removed before the epoxy goes off.

This datasheet might help.

 

[Caer Urfa]

Hi folks, I have just finished scrapeing off all the old antifoul and am looking for any advice,tips or hints as to where to go next . The hull is very clean with just a hint of antifoul still visible. Does this require further sanding? After applying the epoxy coats does it require primer before antifouling and how long should it be left before antifouling? Finally a silly question. Do you use masking tape on the waterline and if you do when do you remove it bearing in mind that if the epoxy goes hard on top of it, it will never come off. Any advice etc. would be very welcome.
Colin

You have to remove 'ALL' signs of old antifoul 'BEFORE' appling Gelshield 200
You say you scrapped it off, BUT you need to go over it with 180 grade sandpaper to give the Gelshield something to bond to, THEN wash it all down with fresh water, THEN clean it with International Thinners No 7, (warning! wear glasses and gloves with this stuff, otherwise it's a hospital job).
Then final wash off with hose and leave to dry.

It says on the tin ok to apply at 5 Deg C, BUT, you want it nearer 10 Deg C.
Make sure you mix it 'correctly' 3:1 and well and allow to stand for ten minutes before use, to get rid of air bubbles.

DO NOT MIX THE THE WHOLE TIN AT ONCE!, apply it in stages.

Masking tape is notorious for not coming off, so remove daily

Have a nice time!
Mike

 

[Slowtack]

Does it need gelshield? Just cleaned off my 25year old hull and found it clean and unblemished original gelcoat throughout. I do not plan to use gelshield. On a previous boat, my scraping nicked the original gelshield so I gave it another coat.

 

[Caer Urfa]

Does it need gelshield? Just cleaned off my 25year old hull and found it clean and unblemished original gelcoat throughout. I do not plan to use gelshield. On a previous boat, my scraping nicked the original gelshield so I gave it another coat.

Clonlara says he has removed all the old antifoul, so I can only assume he has taken it back to the original gel coat/hull or original gelshield coating, so he is correct in applying new coatings of Gelshield 200 to protect the hull again before applying new antifoul coatings.

Gelshield 200 is used to 'protect' the hull and International Pints recommend 5 coats,then I recommend 1 x coat of Primocon, then 2 x antifoul.

Gelshield 200 is expensive (what's not) BUT it can be waisted if not applied correctly, as usual 'read the instructions and data sheets'.

Mike

 

[theoldplucker]

I think that Blakes Gelprotect may be a better choice. Having used Gelshield as well, I found Blakes to be a harder finish to scrape off. Gelshield seems softer.

 

[PeterGibbs]

Hi folks, I have just finished scrapeing off all the old antifoul and am looking for any advice,tips or hints as to where to go next . The hull is very clean with just a hint of antifoul still visible. Does this require further sanding? After applying the epoxy coats does it require primer before antifouling and how long should it be left before antifouling? Finally a silly question. Do you use masking tape on the waterline and if you do when do you remove it bearing in mind that if the epoxy goes hard on top of it, it will never come off. Any advice etc. would be very welcome.
Colin

The quality of the surface prior to applying the Gell Shield is everything. Fine paper rubdown, dried off then wiped all over with meths / degreaser to ensure the best adhesion. If old AF still showing in places, need to get it off completely.

Temperature also important when applying - chose the weather so you have time to apply new coat before the previous has hardened (usually about 3-4 hrs) otherwise the new coat will not "key". Should get 3 coats on per day - GS requires 5 for the right thickness buildup: don't spare the paint! Use the more expensive tape for the waterline - the stuff that can be removed after a couple of days: the GS will not affect the removability of the tape. Suggest you set the tape about 5 mm short of the final waterline, so when finally removed any roughness in the GS edging can be easily sanded before covering with AF - for the best finishing effect.

Use alternate colours of GS for each coat to ensure even application.

After the last GS coat, whack on on A/F primer as directed, again losing no time for the GS to harden. After that you can A/F to complete in your own time.

It's a 3 day job in warmer weather. Rushing it will result in a bodge.

Happy days!

PWG

 

[GrahamM376]

After the last GS coat, whack on on A/F primer as directed, again losing no time for the GS to harden. After that you can A/F to complete in your own time.

I'm in the middle of Gelshielding at the moment - 2 coats to go. If you are due back in the water reasonably soon, you can apply anti-foul direct to the Gelshield without a primer coat but, it has to be done within hours or, the primer coat will be needed.

Before applying any epoxy, get some moisture readings taken. Epoxying a high moisture content hull will lead to problems later.