Epoxy Questions

[Forbsie]

I re-cradled my boat yesterday and now have to embark on 2 majors projects involving large quantities of epoxy.

i) 4 stringers(?) have de-laminated and warped and need replacing.
ii) A faint crack has appeared behind the 3/4 keel where it was pushed up when the boat was last slipped.
iii) A gap has appeared between a beam across the top of the transom and the transom itself. I originally regarded this as cosmetic but now think that the outdrive was pulling the transom away from the beam due to me taking out bolts that I shouldn't have. /forums/images/icons/crazy.gif

Anyway, I seem to have some sort of block in understanding the various types of resins available on the market. I have used the 2-pack SP Epoxy Resin with a fairly open weave mat and a tighter weave ribbon (sorry I don't know the proper terms). I have also seen others using big tubs of West Epoxy Filler and have recently come across a 50 year old book of samples of much finer fibreglass/polyester matting which makes me think that there are loads of products that I haven't seen in the chandleries.

Could anyone explain what products are available and which are best for each application such as coating wood, attaching stringers, filling and finishing?

As ever, most grateful for any advice.

Gordon

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[snowleopard]

there's a tremendous variety of glass reinforcements available. the problem is that the best ones come in 50kg rolls. great for builders but o.t.t. for repairs.

the three basic types are:

chopped strand mat: random fibres, looks like v. coarse felt. not suitable for epoxy

woven roving: interwoven strands, available in tape or sheet form. adequate for most purposes and obtainable in small quantities from glass fibre merchants

stitched cloth: the strands are laid flat on top of each other and held together by stitching. they are the strongest and lightest but only available from specialist suppliers.

resin: SP or Epiglass are the main trade names.

hint: wet the glass with resin on a sheet of thick polythene using a piece of flexible plastic as a squeegee, apply to the repair then squeeze out air & excess resin. wait till the polythene will peel off easily and you'll know the resin is cured.

always abrade well before applying repair and wash with acetone if there's any possibility of grease on the surface.

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[bigmart]

I believe that you will find that Glass Mat for use with Epoxy is different from the standard types which are designed for Polyester resins.

Martin

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[vyv_cox]

Look at <A target="_blank" HREF=http://www.cfsnet.co.uk/acatalog/>http://www.cfsnet.co.uk/acatalog/</A> for good info

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[oldsaltoz]

G'day Gordon,

Sounds like your going to itch for while, good character building stuff this fibreglassing lark.

To reduce the itching, take a very hot bath and pad yourself dry, then smother yourself in talcum powder at once, not after you have cooled off.

Remove everything from inside the boat, or be faced with massive clean job, or a boat you can never stop scratching that itch every time you get on board.

Wear all the protection you can, ear plugs, goggles, a good quality mask - not one of those silly little paper things on rubber bands; long sleeves with taped ends to seal off the rest of your arm, long pants and taped ankles.

Having given you the good news, take a look at the site below, lots and lots of information.

If you find it a bit hard going, fell free to PM me.


<A target="_blank" HREF=http://www.atlcomposites.com/west_system.htm>http://www.atlcomposites.com/west_system.htm</A>


Hope this helps

Andavagoodweekend. Old Salt Oz /forums/images/icons/cool.gif

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[Gunfleet]

and another thing

Can I add an epoxy question? I want to re-trim two cockpit locker covers with teak veneer. The veneer sellers tell me you can use epoxy to glue this but are a bit short on the specifics. Yeah, I did a bit of teak veneering with an iron and a sheet of rabbits foot glue or some such as a schoolboy (ah yes. Mr Churchman. Ask him about his time in the long range desert group and forget the rest of double woodwork). But that won't work outdoors and I keep wondering , how the hell do you use epoxy and then clamp up a great big sheet of veneer? It sounds like a recipe for a sticky mess.

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[snowleopard]

Re: and another thing

the only way is to make a vacuum bag. it's quite easy:

spread glue
apply veneer
cover with bubble wrap, bubble side down
cover with thick polythene
stick down the edges with brown parcel tape to make an airtight seal
make a hole and stick the nozzle of a vacuum cleaner through polythene and bubble wrap and seal around tube with tape
set the vacuum running until resin sets.

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[Gunfleet]

Re: and another thing

Fantastic. Thanks. Don't you sleep?

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[snowleopard]

Re: and another thing

sleep is for wimps, wusses and skippers who trust their crews.

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[kgi]

You could look at the west system website, they do manuals for everything you wish to do and they don't cost that much..........keith

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[Forbsie]

Thanks for your replies everyone.

I have studied the websites and am a bit clearer although I think that I should visit a specialist supplier so that I can see what they're talking about. I just find the language used in the descriptions somewhat taxing if you don't know the vocabulary. Worse than a computer manual!

Thanks again. Glorious weather out there and I'm going down to the boat. /forums/images/icons/smile.gif

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[Forbsie]

Thanks Snowleopard.

That's a great help. Looks like 'Woven Roving' is what I have previously used. I did get a video from West Systems when I did my first repair which was very helpful.



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