G4 - but what G4?

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Ed
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Post by Ed » Tue May 01, 2007 5:25 pm

Hi all, but particulary Chris.....

as a follow on from last post, you will of gathered that I am really thinking of finally using some of the G4 products to coat a boat with.

I have thought about it for ages, but always chickened out or didn't have the right project for it. Well I reckon this boat I am doing may well be a good project to test it with.

But my question is:

<b>OK G4.....but what G4?</b>

G4 Sealer Varnish - also know as 'Damp Seal'

G4 Pond Sealer

Bonda Seal Clear (G4 +uv inhibitors)

G4 sealer is available in colours and is relatively cheap, but the Bonda 15 year white is more expensive.

I presume you use Seal-clear for top coats of clear varnish....or another varnish system.

But any other thoughts or advice?

Also - another question.

has anyone tried yet to remove the stuff? How easy is it to get off the boat at end of it's useful life? I was/am a little woried by the statement that it resists up to 200deg Cent. Strippers often don't touch polyeurethanes.....and of course many epoxies lift so easily in heat that I have seen them come off attached to a boat cover before now. But how do we remove the stuff - and can we do so without harming the wood underneath.


Also whilst asking.....

does anyone know about either of these products:

EP2000 2 pack epoxy paint - 5l at £22.42 +vat

Epicon T500 coating system - 5l at £41.45 +vat

not for this project, but still very competative prices.

http://www.cfsnet.co.uk/acatalog/CFS_Ca ... S_256.html

thanks for all advice.

cheers

eib
Ed Bremner
CVRDA


Jollyboat J3
Firefly F2942
IC GBR314 ex S51 - 1970 Slurp
MR 638 - Please come and take it away
Phelps Scull
Bathurst Whiff - looking for someone to love it

chris
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Post by chris » Tue May 01, 2007 8:51 pm

Ed,
G4 was recommended to me by an Oxford boat builder who swears by it for trad boats. As a product it was, apparently originally designed for just this sort of marine use, but seems now to be only sold as a pond sealer. However I think the tin shows boat as a possible use in an illustration.

I used G4 clear pond sealer (blue tin) on John's merlin 36 2 or 3 coats and left him to then varnish over it. However a year or two on and I think it is just the g4 only on it. - Seems ok still!

My Albacore. Couldn't make my mind up about finish, Especially on the hull (to epoxy or not that is the question etc)in the end it has 3or 4 coats G4 plus 3 or 4 coats Blakes Dura Gloss, outside, topside and inside.

I don't know that i reccomend it unreservedly but here'e how I see the pros and cons and probably why I chose it in the end for the Albi.

Pros
Penetrates deeply and will toughen old, dodgy timber a bit.

Good traditional 'varnish' appearance - that amber colour that brings out a lovely colour in good timber.

Quick to use - it's one of those things you don't let harden between coats, allow 2-4max hours between coats. So 3 coats in a day builds up a great foundation.

Very tolerant of cold and damp for it application. i think it says you can apply in tempaeratures as low as 6dgrees or something. It actually needs moisture to cure it. So a damp winter's day is OK. Certainly no problems with bloom or not curing.

Much less evil vapours than UPC (which I seem to react to nastily) but I'm not saying it's good to inhale.

Not too pricey and is available at good aquatic garden centres or plenty of places on the web.

Very tough yet slightly flexible. ( I especially like the flexible quality.


CONS
seems to dissolve foam rubber rollers or pads - so I reverted to brushes.
First coat can raise grain abit. it is essential to get surface very clean or the first coat is very rough. It doesn't flow and level like a trad varnish .

I tried to wet'n dry it the next day to level some roughness - the roughness stayed and the abrasive paper went bald! seemed Ok after a couple of days though.

Don't know if it's UV filter (one reason for varnishing over)
Doesn't feel like a trad varnish so need to develop a technique that works for you.

Any left overs are bound to be hard by the next time you open the tin to do any touching up. Don't leave a brush overnight in water as it will be rock hard very quickly, acetone will clean, but I did try leaving the brush in a glass of cooking oil ( this work very well for varnish - you can leave a varnish brush all year in oil) but then you need to clean the brush anyway.


On balance I like it but it is not as easy as trad finishes to apply but it's quick and reasonable in price, very tolerant of climate.
Durability and removeability? I'll tell you in ten years time.

With care it can leave a very nice finish without any trad varnish over it.
So..I recomend it with some reservation.
As with all these things it's swings and roundabouts, what the job is and other factors so no easy answer!

Garry R
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Post by Garry R » Wed May 02, 2007 9:03 am

I have used it on Gannet too. Inside I have used G4 pond sealer only while for the outside I used G4 (3 coats) and International although I would now use Blakes Duragloss as I prefer it. All the pros and cons that Chris highlights hold except I would add that it is runny and you have to beware that it can run into pools if you are a bit liberal with it. I did find that if you overlooked an area where it had pooled it bloomed and was still a bit soft. But in the normal areas it penetrates well and goes very hard quickly. Use gloves as it makes a mess of your hands. I deanted it as soon as it arrived into 500ml or 1l bottles to prevent curing in the tin once opened. See the pictures of Gannet inside to see the colour.

Rupert
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Post by Rupert » Wed May 02, 2007 9:26 am

I've also used V8 pond seal which appears to be the identical rival make. I'd agree with what has been said above, but with 1 extra point. If covering with traditional varnish, I've found that even after several days of the G4/V8 having gone hard, it inhibits the curing of the varnish. I assume it is because it is still giving off thinners for a while after you'd have expected it to stop. I have done decks with no other covering, on the theory that if it is supposed to survive all year round in a pond, it must have some sort of UV protection. Having said that, any decks I've wanted "nice" I've covered with real varnish.
Rupert

andrew
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Post by andrew » Sun Jan 27, 2008 9:31 pm

I have just used G4 on the decks of J28.
The deck was a bit fragile having had waterdamage.
The G4 seems to have stabilised some of the opening of the grain.
Two coats of Ravilakk varnish and it looks great.
The pigments in the G4 do bring out the best in the wood without producing any cloudiness.

I phoned the director of Bondaseal to ask about overcoating.
G4 and Bondaseal clear will between the time of being touch dry and curing release a plasiciser which will make adhesion of further coatings poor.
Hence the need to apply after 4 hours or when sanded after curing.
It sanded very well after 2 days.
So far highly recommended.

A local boat yard use 3 coats of bondaseal and one of Ravilakk in one day.

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Ed
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Post by Ed » Sun Jan 27, 2008 11:38 pm

Ah Ravilakk.....nice varnish that.

Where do you get it and how much are you paying for it?

Look forwards to seeing J28 on the water but some photos would be good for the moment.

cheers

eib
Ed Bremner
CVRDA


Jollyboat J3
Firefly F2942
IC GBR314 ex S51 - 1970 Slurp
MR 638 - Please come and take it away
Phelps Scull
Bathurst Whiff - looking for someone to love it

roger
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Post by roger » Mon Jan 28, 2008 9:23 am

Ed

All the above. I used G4 on Shoestring and am very happy with the result.
I applied it in the summer under a perspex roof and it got to hot and bubbled white in places and I had to sand it down. It appeared to be very hard but did come off with elbow grease and wet and dry. DONT apply it in very hot conditions.
Shoestring looks great and I am pleased with the results.

keithr
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Post by keithr » Mon Jan 28, 2008 12:15 pm

Ed

I used g4 sealer on the new peggie 199.

Stripped deck with heat gun, 3 coats of g4 in one day in cold wet/windy barn.

Sanded down after 3 days and one coat of varnish to seal and we sailed her at Boat show.

Very easy to use but dont put too much on the brush.

Looks OK too.
Two Peggies 199,100,
Flying fifteen 1855,
Flying fifteen 204 (now in the barn)
Sunbird

andrew
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Post by andrew » Mon Jan 28, 2008 9:36 pm

Ravilakk is available from the marine megastore at a good price.
http://www.marinemegastore.com/product- ... _97094.htm
I paid £13.50 for 1 litre from a local boatyard.
It was very easy to use with no runs or brush marks and seems to produce a good thickness per coat.
Ed, I will send photos of J28.

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