How much epoxy resin?

[John Abbott]

I am looking at the Tiki 30 and ordered the study plans, but I am unsure from the materials list just how much epoxy is required.  Does anyone know approximately how many gallons would be needed for the Tiki 30?  While I am asking if you could comment on the fiberglass too that would be helpful (in terms of how much, what type and are multiple layers required etc.)  This will help with estimating costs of the project.  Thanks.

[Ian]

I think it very much depends on building conditions and finish required. Also, unless you are confident of a very quick build then I wouldn't buy it all at once.

For costing purposes, especially if you are using WEST which is quite toxic, remember that you should be using:

1) a powered airmask, which you will chuck after 6 months epoxying and need a new one(or at least new visor and seals) I started with Racal Airmasters then had to move on to the Trend one with the motor on top which is unfortunately very tiring to wear (and expensive). I had one with the motor on your belt but it gets in the way inside a hull.

2) thousands of nitrile gloves, shoe covers, overalls, gauntlets, barrier cream etc

3) plenty of cleaning stuff (not acetone!)

I latterly switched to FLAG for finishing details.

I can be very boring about the health precautions that should be costed for and often aren't , as unfortunately being a pro in the wood business have seen a colleague die at 36 with nasal cancer dust related and have researched the subject of wood dusts and glue dusts quite a bit. (Don't start me on MDF!)

[Ann and Neville Clement]

Nev and I have mixed glue with a few friends over the years.  Some are quite wasteful and mix way more than needed.  When building Peace IV, we mixed all our glue in small batches so it did not overheat and go off before being used.  We kept a list going of places which needed a little more glue or small jobs kept waiting where it could be used.  I had lists for low density, micro fibers, colloidal silica, coating glue, etc.  Other folks just tossed any left overs.  Because we used pumps, we made smaller and smaller mixes towards the end of the jobs we were doing that day.  We used cleaned out evaporated milk cans because they were straight sided and we could get everything out of them leaving nothing to be tossed with the can.  This is a big boat and I believe we saved a lot of glue this way.  I know this is not quite the answer you were looking for with your question, but it is related.  Ann and Nev

[Omar M. Rashash]

I held an epoxy clinic for members of my woodturning club this past Saturday.  They were all doing small projects and has the ability to measure as little as 3/8 oz. of mixed epoxy by using calibrated cups.  They almost all mixed 2-3 times more epoxy than they needed.

Once epoxy is applied to the workpiece, the hurry to get it out of the mixing cup, before it fires, is over.  There is usually plenty of time to mix an additonal batch if it's required.  There will always be some epoxy left over, but if you do as Ann and Nev suggest, and plan ahead, you can minimize that waste.

[Tam Dl]

WEST isn't all that toxic.  People forget they commercially built boats and hundreds of turbines with the stuff and had to pass OSHA.  Their shop is not that big, or that high ceilinged, and I believe they said they never exceeded OSHA specs.  It is good advice to protect yourself when using any of these products. 

WEST does seem to affect some people badly relative to contact dermatitis.  Though one guy I know who got all kinds of rashes, eventually settled on WEST, so some of the off brands are just waiting for a good body chemistry match to play with as well.  In any case the key word is "contact".

Actual epoxy use is highly variable, it isn't just the stuff that gets on the boat, it is the waste also.  There is very little reason to sand when building a boat, all wet sections on a boat up to about 30 feet should be done in as few steps as possible.  So you get chemical bonds throughout, don't do any sanding to get mechanical bonds later.  Realistically you are going to have to do a few steps, but think of a single step inside and out as a goal.  The faster you work the lower your exposure also. 

A 30 foot boat should take about 4 hours to sand, if you are doing more, you are doing it wrong.  I had a chance to work with Jim Brown at WB, and he and his son did the final sand on the 23 foot tri they were building while we were at breakfast.  Like 2-4 man hours, that is about sixty feet of hull, so probably compares to a 30 foot cat hull.  Russ Brown, who has just published several books on epoxy and finishing is eqally fast.  When he hit the west coast, jaws dropped at how fast he was.  It isn't just hussle, it is knowing which steps to do in what order. 

Think for a moment of the internet, where people pick up scraps of info that have no relative position in the whole project.  They do one part, then hit the computer.  You can't get professional results that way.  There are doubtless many ways to do any of the jobs in a build, but once you commit to certain processes, there are far fewer ways to proceed from there.

An understanding of drywall work is useful (I mention it because many have done some), the basics of which are, complete all steps on the whole project at once, never move on to another step until one step is done.  This means in an ideal world that your crew is large enough to complete a step in one wetting/cure.  Solo you can do up to about 30 feet, but at least if you know what you are doing, you can leave the wet edge to a manageable size. Each step should be fully covered by the next step so that there isn't any sanding (there is always the odd booger to knock off).  If you don't do that there is all kinds of confusion, one is fairing one part, while one hasn't fully covered glass somewhere else.  Know what steps are required, and do all to completion then move on.

Cut as much epoxy off as you can to reduce sanding.  This also depends on how you laid out your fabric, and bog, etc...  But you should be able to get rid of a lot of sanding by quickly passing over the boat with scrapers, saws, files, etc...

Sanding is a whole subject all it's own.  I once got a prize for a mag article on that subject.  But baiscally big sanders, coarse grits, do not run the paper longer than it cuts.  Faffing around with underpowered ROSs making lots of flowery dust is amateur hour.  If you can see a real sander at work, it is worth the price of admissions.

There are a lot of places where epoxy can be saved, the epoxy scantlings in wharram boats are robust.  But that involves diverging from plans which is a risky business.