Which Epoxy?

[Tomsk]

Just starting to build a 14 foot 'stitch and glue' dinghy from Selway Fisher... most materials have now been purchased, but I'm still lost in the 'Epoxy Minefield'.

1) Has anyone any advice that they would like to impart re: the use of said epoxies and resins?

2) Has anyone any preference (and a reason for) any particular brand / formula (West / SP / International etc)

3) oh bug*er, two questions are enough /forums/images/graemlins/blush.gif

Thanks in advance!

 

[fluffc]

Personally, I use West Epoxy. Just built a dinghy stitch-and-sew with it, see Part 1 and Part 2.

Preference for west is it's widesread availability, and just it's what I've 'grown up' with.

Used resin with normal 205 hardener. Also 403 Microfibres.

When chosing a resin, consider that you will probably need more than you first thought, so need something readily available. I went through approx 6kg of resin in my dinghy, including epoxy coating the whole boat. (Approx 4.5kg without epoxy coating).

It is VERY MUCH worth buying the dispensing pumps - saves a lot of guesswork.

 

[fluffc]

[No message]

 

[Tomsk]

[ QUOTE ]
Personally, I use West Epoxy. Just built a dinghy stitch-and-sew with it,

[/ QUOTE ]

And very smart it is too!

Thanks for the advice.

 

[Tomsk]

I thought about doing a questionaire thingy, but they don't seem to be used too much in the Classics Forum... /forums/images/graemlins/ooo.gif

 

[dur]

Agree with the West. Did a little one 5 years ago - seems to be holding up!

http://www.gaff-rig.co.uk/our_other_boats.htm

Also agree with getting the dispensers. Have had mine for years and they are still going strong.

I tried the MAS (?) epoxy once. It was sold as being easier to wet out and prime etc. and it definitely was. However when filleting with colloidal silica (nasty) and microballons mix, it would slump as soon as my back was turned so I went back to West.

 

[Porthandbuoy]

I prefer West epoxy, but whatever system you use follow the Health & Safety advice to the letter. If you don't you may well end up with a nasty case of dermatitis or lung cancer.

 

[Lakesailor]

I don't know what make I use. I get it from Fyne Boats who are but a couple of miles away.
I used wood flour to stiffen the mix. The balloons and silica bulk it but don't provide any structural strength as the silca just slides over itself.
The wood flour (dust) also has the advantage of self-clouring the resin.

 

[savageseadog]

Why are West and other boat epoxies so expensive. Industrial epoxies are about 7 pounds a Kilo in small quantities ie 25Kg

 

[Lakesailor]

I don't know. is it because of the different setting times? Or just because of the small quantities and the repackaging.
I wouldn't want 25 Kgs of the stuff.

 

[Superflid]

For small quantities I found it easy to measure into a plastic container on a digital kitchen scale. Any remains in the container will come out easily when it's gone off.

 

[Lakesailor]

Yoghurt cartons or the bottom of plastic milk bottles are good.
I just use wooden spatulas and measure and mark them in the correct ratio (ie. 2 and 1 ) to pour the resin and hardener in. Always seems to work.

 

[Superflid]

[ QUOTE ]
the bottom of plastic milk bottles

[/ QUOTE ]

That's what I use..... /forums/images/graemlins/grin.gif

 

[fluffc]

[ QUOTE ]
the correct ratio (ie. 2 and 1 )

[/ QUOTE ]
The correct ratio (by volume) for West with normal hardners (205 or 206) is 5:1.

 

[Roach1948]

I have heard that SP is almost the same formula as West (as I understand it a case of the corporate formula/skills migrating) - which is why I have used SP - slightly cheaper too, and not an issue using WEST additives.

I reckon more important than an exact ratio is the length of time you mix - AT LEAST one minute in both directions is my advice.

I don't use any old youghurt pots or milk containers anymore - an large wide and shallow ice cream container is much better if you want to prevent an exorthermic reaction.

 

[Tomsk]

The SP epoxy would appear to be half the price of the WEST stuff, unless you want the 'clear as glass' stuff in which case it's about the same. Is the WEST totally clear? Perhaps an option would be to use both in different areas and save a few quid.... /forums/images/graemlins/smile.gif

 

[Lakesailor]

Well obviously the resin I use is not West.

Do you think I chose a 2:1 ratio at random?

 

[Tomsk]

I think SP is 2:1, but more importantly, did it do the job for you?

 

[Keith 66]

I have used West and SP which appear to be identical products, nothing to choose between them.
The prices are eye watering.
Ciba Geigy the makers of Araldite used to do a comprehensive range of industrial epoxies but are hard to get hold of.
Regarding Safety the Hardener is normally the nasty component, i got some on a webbing watch strap once and it gave me a lovely chemical burn that took ages to heal up, a first class lesson in health & safety!
I feel that epoxies are overrated and we shouldnt forget that
for underwater work Rescorcinol still has not been bettered and for spars Aerolite is still excellent.

Epoxy though is great for the less accurate boatbuilder as
"If the Joint does not fit fill it up with glue and s***"

 

[Lakesailor]

Certainly has done the job. The only thing I have against it is the hard work rubbing down if you want to get a good varnish finish.