best glass to use

I’m trying my hand at a scratch built hull, what is the best glass to use,and epoxy?

Mike - my choice:

I use 4 or 6 oz. glass for hull building with Gougeon Brother’s WEST SYSTEM<font size=“1”>tm</font id=“size1”> epoxy system - resin, hardner, and fillers. Exterior layer on hulls I use 1/2 oz. glass cloth.

Generally I purchase my glass from RAKA out of Florida, unless local WEST MARINE (no relation to WEST SYSTEM<font size=“1”>tm</font id=“size1”>) is having a sale off the roll. Lately I have found less and less need for the 6 oz. stuff, as it takes too much resin to fill the weave.

I used WEST SYSTEM<font size=“1”>tm</font id=“size1”> for my big boat, and it simply has carried over to the little ones. Lots of other brands that people have used and recommend too.

Just don’t use the “rubbery” kind of epoxy you can get at hardware and home building centers.

there are two epoxies that i use for carbon work:

west systems for repairs, fillers, and non-elements conditions (i.e. not left rigged up and in the hot sun, such as masts, tubes, poles, etc.).
pro-set epoxy for structure building and in-element conditions

west systems has more elasticity than pro-set. it also kicks quicker than pro-set, but has a lower ?high end yield strength? than pro-set. pro-set also has a ?higher glass transition temperature? rating, meaning if you have something that will be left out in the elements, it will take much more heat (than west systems) before it distorts and looses it?s original shape. obviously this is not a large concern with r/c yachts, but can be hugely important in full scale.


SP systems Ampreg 20 epoxy. Dont use glass except for moulds. Carbon is the stuff!

Luff 'em & leave 'em.

well put matt!
wish the price of ampreg over here (OZ) was as cheap as over there.

ahhhhh sp systems ampreg 200 is the way to go (so im told(im too cheap to buy it dew to the fact that is more then doubly the price of most outher epoxies even west(which is crap and not a trew epoxy)))

Never hold your farts in.
They travel up your spine, into your brain,
and that’s where sh*+y ideas come from.

Thx to all, your advice was very helpful the hull came out awsome, (for a first planked hull). got alot of sanding ahead though. i have taken about 40 detailed pictures of the construction i will try to post later (not all forty)
anyone interested please inquire. detailed instruction is very limited or i just put my tree stand in the wrong place… again thx

… just to note here, West Systems is <u>not</u> in fact “crap”. That is just one persons opinion here.

i have to agree with greg here. west is NOT crap. i used it for a while. I dont mind the stuff , BUT now i use mgs firbeglass. i find the resin to be harder, and easier to apply. even though the mgs need a weight scale to use. west is used by a pump. west is also cheaper. you should kep that in mind
long live the cup and cris dickson

<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by michaelb

even west(which is crap and not a trew epoxy)
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>

Boy - I’m not sure I could agree with this statement! I hate to think of the number of kayaks, Tornado cats, DN Class iceboats, 1/4, 1/2 and 1 ton boats, one design classes and PHRF classes tha have used and rely on WEST SYSTEM<font size=“1”>tm</font id=“size1”> products. Too numerous to count - but “ADRENALIN” (Formula40 trimaran) and “SLINGSHOT” (World Speed Record attempt) and Phil Weld’s old trimaran “ROGUE WAVE” (from OSTAR days) are just a few examples of boats that have a “few miles” on them and actually RELY on the stuff to hold their hulls together !

Also Michael - you might want to drop an email to Meade Gougeon and discuss how it is that his 35 year old trimaran is still kicking ass in the Port Huron to Mackinaw Island races - it was built of this same “crap” and is still very competitive AND fast on the Great Lakes. In my opinion, and I could be wrong, WEST SYSTEM<font size=“1”>tm</font id=“size1”> products have been holding boats together far longer than some “other” companies have been in business.

As far as “not” being a true epoxy - upon what do you base your opinion? Just curious.

Perhaps michaelb has been holding his farts in again…

Will Gorgen

lets get back to the topic guys
defending a product against one person is not realy effective. i do not agree that west is crap. but if mike want to call it crap than that is his right, we give our opinions here. like i said before . i dont use west system epoxy but i am not going to call it crap. i like mgs .but like i have always said everybody thier opinion.
long live the cup and cris dickson

I would have to back up michaelb, simply because firstly he is a pro or near enough the end of his boatbuilding aprentiship to know what he is talking about, and secondly because there aint many boatbuilders round here still using west, even though the price is cheaper. West systems stuff is not exactly crap, but there are better epoxies out there now.
BTW does anyone use any Plexus products? cant remeber the name of the stuff I get to use but its great for making damn unbreakable but slightly flexible joints. Often used for the hull/deck joint on big boats, super expensive stuff…

Luff 'em & leave 'em.

rather than just slinging mud by saying “west is crap”, why not substantiate your P.O.V. with some facts and empirical data?

i, for one, would like to hear some factual reasons for your statement.


I’m sure that there are better epoxies out there but West System epoxy has worked great for me for the last 15 years on everything I’ve done from my full size mahogany Chris Crafts to my R/C sailplanes to my sailboat. So far, even if there are better epoxies out there, I don’t need anything better than West Systems.


Matt & Cougar -

I don’t think it is an issue that Michaelb doesn’t like using WEST SYSTEM<font size=“1”>tm</font id=“size1”> products. That is his call, and his personal opinion. But one needs to remember, that making these kind of claims in a public forum, can raise issues well beyond personal likes or dislikes. In fact, I think speaking for most of us, we all would like to know what led him to make such a statement. WEST<font size=“1”>tm</font id=“size1”> has been out as I noted, well over 35 years and is a tried and true product. As I asked, I certainly would like to know what facts he based his “crap” statement on - or was it just a “slip of the fingers at the moment”?

If he doesn’t use Ampreg 20 (or 200 ?) it would be interesting to know what he does use and how many boats have been built from the product. As to his “pro” status, that too can be an issue of discussion. Like the Chevrolet versus Ford debates, we may never agree, but that WAS a pretty strong and unsupported statement.

Reminds me of a different post where a person was called a “hacker” without proof.

Now that we are back to normal (more or less) on this site, it would be nice to quantify statements with some facts or examples. I believe we all would be interested in finding out how he came to this conclusion and under what circumstances. I know a lot of people who hate WEST<font size=“1”>tm</font id=“size1”> simply because it is usually a 5:1 mix - so their first (last?) project never cured and stayed like chewing gum because they use 5 pumps of the big pump (resin) and 1 pump of the little pump (hardner) not realizing that the pumps were pre-metered for a 5:1 ratio, simply by using 1 stroke of each pump. Some prefer a 1:1 ratio, and some use polyester resins instead of epoxy - but usually they express the reasons why.

Yep, Those pumps were the one thing I didn’t like about West system. Only because if I leave them sitting around, the daily temperature changes would make them pump out all over the table.[:(!][:-banghead][:-boggled][:-censored]

Hint -

the mini-pumps work much like a syringe with a check-valve. There is a plunger that pulls the product (resin or hardner) up the pump “shaft” and there is a stainless steel ball bearing that is supposed to close off the plunger to allow the epoxy to be dispensed by the pump.

After cleaning my pumps very thouroughly, I found the same problem - whether clean or “dirty and well used”. After dumping a 1/4 full butter dish, I finally got mad and tried something out - so far it seems to work - and if there is any “droozle” it is really minor.

Take a very small punch (small nail) and put a hole in the top of the can near the middle. This relieved the pressure build up inside the can and prevented the pressure from forcing out the “droozle” when the can/contents got warm. (Doesn’t happen in the winter !)

Keep the hole as small as possible, and if not using for some time, just put a piece of duct or masking tape over the hole to keep out dust and dirt, but leave a small opening to allow pressure to bleed off. I usually create a “channel” by making a fold in the tape. When ready to use, pull tape, use and when done for a while, add a piece of tape again. For long periods of storage, remove the pump, allow excess product to drain into can, and put the original cover back on until you need it again. Pumps can be stored in plastic freezer type bags.

  1. Do not drill - as small shavings might get suspended in the resin/hardner and get drawen into the pump and mess up the sliding plunger. Use a very small nail and only make the biggest hole necessary to vent pressure.

  2. WEST<font size=“1”>tm</font id=“size1”> has a discoloring process as it ages. The hardener will go to a dark purple/burgundy. This is caused by time/age/temperature but IT DOES NOT affect the physical properties of the epoxy mix in any way except in color. Obviously you can’t clear coat your hull with the darkend stuff.

didnt know i would create such a fuss
it is really my oppinion that west is not as good as some of the outher epoxies out on the market but i will try to explain my reasons to you they are my thoughts and mine alone.
west does not have a catalised indicator/cure indicator. i know that fgi does and im pritty sure that sp does as well

the resin starts of a darkish blue when uncatilised when you add the hardner the product goes clear. after the product has gelled or started to go off the broduct turns a dark blue again then after a normial room temp cure it starts to go clear. when it is finaly cured it is a clear but has a slight blue tinge to it. when you post cure the resin the resin goes from a blue to clear then starts to get redder the longer/hotter the post cure.

west is a very thick resin. so it takes longer to wet out than alot of outhers it would be no good for resin infusion whih is the way of the fucture suposed to fe as good as a pre preg layup.

west is a very rubbery epoxy

west only comes in 3 hardner types
fgi has about 10
sp has about 7 which can be mixxed to get the right amount of working time. it also has a pre preg hardner

i have known west to go milky when used on clear strip planked sea kyacks in which when the rep was called he did not want to know about it, they were told it was a usere error and was out of there hands.

as far as i know west only makes one type of epoxy. where as sp makes 100s for all diffrent applications.

they all make able to supply add ons and consumibles

price while west is cheap fgi is cheaper and sp is expensive but you get what you pay for.

these are just my thoughts take them for what you paid for them and have a try off all the diffrent resins i have and i am happy with the fgi it is good and hasnt let me down. while the sp is not cheap it is a blody good product i know that all they top guys who are building top boats in aust are using sp systems resin i know skandia was built with it

but these are my opinions if you dont like them let the bord know about it and explain your self

dick im not saying west will not work because we all know that it does it has been proven to work. im just saying that there are a lot better products out there which i think are better.

dick have you tried any other epoxies? if so what and what did you think? why do you like west so much

Never hold your farts in.
They travel up your spine, into your brain,
and that’s where sh*+y ideas come from.

just a hint about the pumps through them away and get a set of digital scales much more accuriat and can be a lot cleaner if you are a good porer as to what glass you are using it depends on the hull size and class rulls for an international one meter the total cloth witght is about 300 grams all over and a nouther 100 in load arias
but as i said it depends on size, construction and class rulles as to what glass

Never hold your farts in.
They travel up your spine, into your brain,
and that’s where sh*+y ideas come from.