Epoxies and Adhesives

[cjackson]

If you gentlemen could help me out. I really need to get smart on expoxies and adhesives...it looks as though #387 still has quite a bit of glass work to do. After reading thoroughly through a lot of posts on the site I did not find one cohesive thread, just for the purposes of explaining the best types of epoxy systems, sealants, adhesives and so on...

Ebb,
You seem to have a tremendous knowledge in this area and are always willing to offer an opinon. If you could give a humble beginner, a quick tutorial on what products I should be looking for I would be very thankful...

Chris

[bill@ariel231]

my tool of choice for Ariel231 was West System (appx 22gal in 5 gallon pails for the recore, and keel repairs). Other epoxy systems work just fine as well, it was just a question of easy over the counter availability (in the mid 90's) as Jamestown Distributors was located between my house and the boat. West has a nice book on use of thickening agents etc.

good luck, you are going to have some fun.....

bill@ariel231

ps. lets see what mr. ebb's favorite brand is.....

[commanderpete]

Epoxy resin is used for repairs, reinforcement, fairing, filling holes, etc. Almost always used in conjunction with various types of cloth and/or fillers.

I've used half a dozen brands, they all work. Proper measuring and mixing is more important. Its harder to screw up the measuring with a 1:1 or 2:1 type of epoxy.

Polyester resin is not generally used, except in new construction, and only because its cheaper.

Adhesives. Epoxy is a glue. There are other types of glue. 3M 5200 is an adhesive. There are some boat repair projects that require an adhesive, but not many.

Caulk/sealant. Primarily used to bed items to the deck. Deck hardware moves slightly, so you need a flexible and watertight bond to prevent water intrusion.
Many different formulations. I prefer the Sika products or 3M 101 over the Boat Life products, but, again, they all work. Stay away from silicone.

Small rant here:

You will see alot of debate on the internet about the merits of one brand or another of any type of product......epoxy, paint, varnish, etc., etc.,
everything. I'm not convinced there's a whole lot of difference between different brands of the same type of product.

Good surface preperation is half the battle. Proper application is the other half.

Every product will work if properly applied. Nothing will work if it isn't.

[ebb]

Like epoxies, there are different brands of advice.
And the problem comes in choosing.
If it's not a problem it's a buffet.
If you truly new at this tho, buy three books on the subject.
That will give you a base to speak from. The language.

There are certain associates here, Mike Goodwin and Frank Durant are two
who have spent lifetimes in and around boats,
who transcend 'opinion', who get things done.
And commanderpete knows when how and whereof he speaks.

Give the panel here an idea of what you want to do.
Gotta have some idea of what order to put things into,
and what the priorities are.
Maybe there is an easy project to start with.

I would be willing to discuss my 'opinions' with you on the email option here,
as I can get pretty tedious, I know. But I may make more sense
if there is a back and forth. And an actual project in hand.
I'm no expert, just up to my eyeballs in glue and adhesives on and in an Ariel for more than 4 years!!!
That's my perspective.

You have to work with epoxy to understand it.
If you've done any carpentry you are half way there.
Like C'pete sez, epoxy is a glue... with certain inalienable properties.
There are tricks and jigs and methods that will make it more fun.

When you look back you'll wonder what the fuss was all about.
But you'll also be wondering where the time went.
and all yer money:

[Mike Goodwin]

Right now I'm working my way thru 20 gal of fgci.com 1:1 epoxy adhesive and 1:1 laminating resin .
I've used WEST , RAKA , US EPOXY, SYSTEM 3 , MAS, EVERCOAT, SMITHS, and a few others you have never heard of and can't buy without a licence .
It all boils down to, they all work . If you feel like spending twice as much as you need to then by all means use WEST system ( it is the Microsoft of epoxy , I prefer Linux ) .

The fact is , that all epoxies a strong enough and waterproof enough ( vinyelester resin is more waterproof ) starting at 1:1 mix . The higher mixes are not necessary in 90% of boat building and repair , so why use them? They cost more and are more toxic the higher the hardener ratio gets , 5:1 being the worst of the bunch.

I started doing testing 30 years ago and found out then that epoxy was stronger than wood . I was using epoxy 40 years ago , it was made by the Gulf Oil Co. , used some by ESSO too ( Exxon to you whippersnappers ).

[mbd]

... appx 22gal in 5 gallon pails for the recore, and keel repairs

Bill, you used 22 gallons of the stuff??? How extensive was your recore?

[bill@ariel231]

yup 22 gallons.

For A-231, the resin projects included:
deck recore - the whole deck from the cockpit forward plus the veeberth from underneath.
coach roof (port side)
hull-deck joint
replacement of lower 1.5 foot of the keel
relamination of the bilge
fabrication of new engine mounts (laminated from 3/8 ply)

the stuff goes fast.....

The boat still floats on her lines since the same volume of material was ground off in the rebuild.

As I said West Systems was available over the counter in '95/'96 while MAS and other brands hadn't hit my local marketplace.

had I known at the start of the project I'd use that much I'd have ordered a 55gal drum. As it was, the project always looked to require just 5 gallons more (until the next demolition project began).

bill@ariel231

[Sprite]

Sika is the product to go with if you are doing deck fittings and bonding stainless steel or aluminium. 5200 does not bond to SS or 4200 or 101. 3M reps will tell you that. Sika a Uniroyal product does bond to SS. You can check with practical sailor as far as the right sika product is.

John

[ebb]

John,
are you saying:
go with a polysulfide caulk rather than a polyurethane adhesive?


For bedding fittings like stanchion bases that would be that way to go.
So that down the line they could be disassembled and rebedded
when the rubber looses its bounce -
which it will.
Plus, polysulfide lasts twice as long as polyurethane in the sun.

5200 is a very stiff material with little flex and is attacked by solvents.
Polysulfide is a pretty stable synthetic rubber. Just heard that Cetol will permanently soften it.
But that problem (solvents) is usually reserved for p.urethane.

BoatLife's (silicone/urethane) LifeSeal may be another way to go. along with 4200
(silicone? modified p.urethane), for bedding metal fittings.
Both these expensive compounds come in smaller squeeze tubes.


But, I do believe that 5200 glue will stick to s.s. just fine!
But embedding stainless steel in rudder is a bad idea! Promotes crack corrosion.

Read what NFM (New Found Metals) has to say about bedding metal with butyl!

[Sprite]

Ebb,

You should check out the Practical Sailor Article. It says 5200, 4200, and 101
do not bond to Stainless steel. 3M's reps don't recommend it's use with
SS. They will refer you to a Uniroyal product to use on it. If 3M says their product does not work on SS I'll take their word on it. I know it started
with an "S" but I'm not sure if it is Sika.

No Offense intended

John

[ebb]

Hey John,
just discusion here.
I guess the key word is 'bond'.
I would like to see that article and you can't find it on the intractable and unhelpful P.S. internet site.

My thought above was that you wouldn't want to bond stainless steel fittings to your boat if you have to take them apart sometime later. Pretty well established.

And if 3-M says don't use their polyurethanes with stainless which is pretty common on boats these days, I think it is well worth posting that info here from the 3-M source. I've personally haven't heard this flat prohibition and suspect that it may be a context to this statement I'm unaware of. We all need to know.

The trouble is that each one of these synthetic rubber goop companies make silicones and p.urethames and p.sulphides and hybrids. It may well be that a particular product is not suitable for a particular purpose. But that's just it: What and Which?