C-Forum

Does anyone have any experience with this product? Because of the long pot life I am considering using in for the boat I am building, but I have no experience with this product.

Thanks,
Paul

http://www.fibreglast.com/showproducts- ... ins-5.html

I haven't used that brand of epoxy.

But if extended "pot life" is desired, why not consider any of the various resin/hardener combinations offered by West Systems?

You can get plenty of viscosity and pot life variety from West Systems. The advantage in using it is that there is lots of information available from West, and if you buy from C-boater John Sweet, he is likely to share his extensive boat building experience and product knowledge with his new customer...you.

Remember, the most important piece of boat building equipment in your shop is an experienced helper/builder. A knowledgeable supplier is only slightly less valuable.

May I suggest a couple of thoughts with a new builder? (Welcome to a small and dedicated group of eccentric paddlers!)

1. "Pot life" means different things to different vendors and manufacturers. Comparing pot life between various brands is really just an idiot's delight. There are too many variables and ambiguous terms to get any meaningful comparisons or reach any conclusions about which epoxy will work best for your situation.

What you are likely most interested in as a new builder is "wet life". That is the time period when the mix is liquid and you can do the laying-in and squeegee work inside your mold. Once the wet life is over, you will have no chance to move the mix around among the fibers.

2. Temperature is the most significant variable effecting wet time that is within the control of the amateur builder. Ten degrees change in temperature is a big deal for most epoxy formulations, including the system you are considering. Because proper ventilation is a significant safety factor, temperature control becomes even more difficult.

3. Epoxy is subject to rapid UV degradation, unless protected by outer layers of paint or gel coats (advanced skills for a home builder).

4. Epoxy, at more than $55 per gallon (in five gallon quantities, which is what you want for boat building), is the most expensive resin system.

5. Vinyl ester resin is cheaper than epoxy; it is just as good for making strong whitewater boats. I think it will give an equally strong hand-layup laminate. It is superior against UV degradation.

Most importantly, vinyl ester is much more easily controlled for wet time (given the same temperature environment) than epoxy.

WARNING: Be careful when handling the MEKP hardener in vinyl ester systems! WEAR EYE PROTECTION! Use a graduated syringe to dispense MEKP into the resin. Stir mix slowly and carefully until the MEKP is fully dispersed in the mixture. Do not get any MEKP or resin mix in your eyes. Clean non-disposable tools with acetone before mix hardens.

6. For your first few boats, use vinyl ester resin. It is easier to use, and I think it makes better boats, anyway. Practice mixing the resin and hardener by making some sample parts. If your mold builder did a cockpit rim mold, lay-up one of those before you drop a couple hundred dollars into your hull or deck molds. This will help you learn how much MEKP to use to get the wet time you want.

I noticed that you are from a nearly tidal area of Maryland. Here is another factor to consider when laying up a whitewater boat:

All resin systems are subject to the effects of temperature and humidity while the boat is being built. Most of the effects are not welcome.

You really have to choose the date and time you build a composite boat carefully. High humidity and high temperature will work to quickly reduce the benefits of placing expensive materials into your mold. Boats constructed under such conditions usually exhibit very ordinary properties when they have left the mold.

If the air temperature in your boat shop is less than sixty degrees, or the relative humidity over 60%, then wait until another day to lay-up a hull or deck.

If the temperature in the shop is going to get over 80 degrees, then expect the resin mix to "go off" in record time. This is very hard to predict, but in piedmont of Maryland, there are few, if any, good summer days for building boats in a shop that is not climate controlled.

If you are fortunate and are working in an enclosed area where you have cooling/heating equipment and humidity control, you are going to have to provide a fresh air source for breathing. All of this is expensive to set up and cumbersome to operate.

Vacuum bagging is an alternative to hand lay-up that eases some of these problems. It requires more equipment, however, and more than a little extra care with technique and procedures. Having an experienced guide for bagging a boat is almost imperative to avoid a disaster.

That is why most home boat builders restrict hull and deck construction work to spring and fall seasons only.

Since building in high heat or humidity is likely to result in a weaker whitewater boat, summer boats are usually made of e-glass and polyester cloth using vinyl ester resin. Using expensive epoxy resin or aramid/carbon fibers returns little extra value for a summer (or winter) builder.

Actually, I will be building the boat in New Jersey this fall (time and money permitting). I have access to a detached garage there where I can make a mess and no one will care. That will also give me some temperature control as well.

When I talked with John Sweet he recommended a layup of Polyester/glass/g/p/g for the hull and g/p/g for the deck. I think i might add another layer to the deck. I was also planning on vinylester resin, mostly for the cost.

In the mean time, I have been reading and asking as many questions as I can. I owe everyone who has replied to me a thank you, I have been learning a ton.

Thanks,
Paul

You seem to be in excellent hands and proceeding with due diligence! Bet you build a nice boat, too.

If you do add another deck layer (a little more money, btw), what cloth will you use and in what position? John once told me that about 30 oz of cloth made a very strong deck for a cruiser (not racing) boat. He is suggesting 25 oz for your three-layer deck, so that is certainly going to be enough for most paddling purposes, don't you think?

Consider the wisdom in what he has suggested so far:

1. Polyester on the outside layer of a five layer (40 oz) hull for good abrasion resistance and flex strength,

2. Two glass core layers between the poly layers to give a stiff core surrounded (and contained) by the more flexible cloth,

3. Glass inside layer to facilitate outfitting attachments and inside seaming, and reduce hull flex when working the subsurface river currents.

Because this is your first attempt to pull a boat from your mold, resist modifying his suggested lay-up. Give up some of the features you want in your "perfect boat" this time around.

That way, if things don't turn out exactly right (my first really nice boat was the fourth or fifth one, depending on if you count the one hull and deck that ended up in a scrap heap), you won't have as much money invested in materials.

You can likely sell it for the cost of the materials you have in it, and pocket the experience as profit. Doing so will pay large dividends in your next build!

Btw, consider how you are going to dispose of your construction waste. Most of it will be unwelcome at the landfill, and some of it will be toxic and quite hazardous. Just plan ahead to take care of this so it will not "pile up" on you!

Fall is an excellent time to build in a covered, enclosed, and unheated workspace. Try to use a couple fans (intake and exhaust) to circulate fresh air from outside while you are working with the resin. Box fans will be on sale soon at Wal-Mart, etc. You want fans that will move some clean air in (and the smelly air out) without blowing dirt and dust around and into the mold, so look for fans with a low speed setting.

Clean the garage (shop) area well before starting work. Loose dirt has a way of finding its way into the mold wax, release film, cloth, and eventually the laminate.

Do the cloth cutting, mold waxing, resin container positioning (the mixing area should be separated from other operations), small tool prep, etc., in the days before you plan to lay-in. If you use a release agent, follow instructions carefully to assure even application and adequate drying before resin is applied.

Get your shop ready with a large trash can, some water to wash your hands with, a fire extinguisher placed near the exit, a designated place for tools requiring cleaning after use, lots of paper towels in strategically located holders, emergency eye wash cup that you have practiced using, and as much clean surface area at a working level as you can manage to set up.

Consider building a boat dolly on wheels or casters. An overhead sling setup is a luxury, but well worth the effort when doing inside seams.

When the weather forecast is for sunny and dry weather, get everything ready to mix and lay-in. Get plenty of rest, and an early start in the morning. Some say the humidity is less earlier in the day, and the temperatures are usually better for moving resin around, too.

Do the deck first. Yes, color resin is more difficult than clear, but there are fewer layers (and less money) to deal with. On second thought, ask John which part to do first. He has seem more first-time builders than anyone. (The appearance of my first deck was dam near ugly because of uneven resin distribution. The mix started to gel before I had finished getting it pushed around and the excess removed. The result was a splotchy mess of vivid color highlights and a faded, mottled background. It was the product of sloppy work by an inexperienced builder!

I know this information is all in the books, but these are some of the things that come to mind as I look back on my limited experience as a builder.

And it was all fun!

Interestingly, at a training camp some years ago someone who had professional credntials in human physiology gave a talk in which he said how long it took for a solvent on your hands to get through the bloodstream to your brain &/or liver. It was unbelievably fast. Lots of folks who work regularly with such chemicals & are sloppy about it end up with health problems. It is easy to say "Oh, I'm just doing a little bit..just this once" . I once took a class in fiberglass work & was totally shocked at the lack of safety equipment. They guy who taught it could barely breathe. A year later he was dead. I still wonder what the school that sponsored it could have been thinking.

Also, WRT epoxy, it is quite easy to get sensitized/alergic. I've heard of folks who cannot sit in the epoxy boat they build without breaking out. May be the case with other materials as well, to a lesser extent.

(My first job was as a flunky in a chemistry lab. It was a joke among chemists that all organic chemists beyond a certain age were -- well -- a little sappy, at the very least, from all the weird exposures.)

So just be careful & use good judgement.

Wearing lung protection while cutting and handling fiberglass is a very good idea.

Such protection can be as simple as a cloth or paper mask that fits over the mouth and nose. At about $1 apiece, the protection is cheap. Cutting fiberglass cloth with scissors will kick small, almost invisible glass fibers into the air. If you are not wearing a mask, you will inhale those tiny fibers. It can't be good for your lungs.

It is very easy to ignore this simple safety procedure. Putting on a mask is a hassle, and after a few uses, it seems to be a futile effort (because the mask will be dirty from your hands and ill fitting because of moisture and creasing/folding.)

Avoid the temptation to proceed with your fiberglass work without donning a new mask. Those glass fibers remain in the air for some time, and in your lungs for a considerably longer time. Have several of the disposable masks available in your boat shop, and keep them in a cardboard box until you are ready to put them on. If you keep a box of masks in the same container as your cloth cutting scissors, you are likely to use them more often.

Of course, sanding FRP is a threat to your lungs, too. Protection is needed against the dust particles that will be floating in the air whenever you abrade this stuff. Be prepared with a box of masks in your sandpaper storage containers.

Make your all your protection (mask, disposable clothing/gloves, ventilation, hand washing area, barrier creams) readily available and use it as much as you can. If you get sloppy, resist continuing to build until you are in a more safety-conscious frame of mind!

The health threat is subtle, cumulative, and may not become apparent until long after the boat you are building is busted up and stuffed under a porch somewhere.

Resin use requires more than the particle protection for your lungs that paper/cloth masks provide. Your brain, liver, etc. require protection from the chemical vapors of those resins.

Get yourself informed about the care and use of chemical filters and respirators. This is going to cost you a lot more than a box of particle masks, but the health of your major organs is at stake. Be sure you know what you are doing before opening a container of resin or hardener.

Boat building without a well-fitted respirator is very risky behavior. Unless you paddle without a helmet and a PFD, it may be more dangerous than any rapid you will run in your new boat.

I'll also add that IMhO there is no better area to work in than a covered space outdoors (or really well ventilated garage (e.g. door is open, and door at back has a fan, etc...)), assuming temp. and humidity are reasonable (nothing like a good sept. or oct. day up here...dry and 70 (when we're lucky)).

Respirators are necessary, but I'd MUCH rather don one in an area that isn't thick with fumes.

Latex gloves are another necessity for building. It IS possibly to get by without them for small repairs (lay up everything on saran wrap-never touch the epoxy), but even then it's best to wear gloves (it's amazing what your skin will absorb...look online for more info on skin absorption rates if you want to be frightened...)

5. Vinyl ester resin is cheaper than epoxy; it is just as good for making strong whitewater boats. I think it will give an equally strong hand-layup laminate. It is superior against UV degradation


Can you use vinyl ester to restore a sanded gel coat finish? Or Is a paint needed.

Are the $30-35 respirators sufficient for working with these chemicals- it has disposable looking cans for filters- and how many hours or how many used do you get from a can?

Bill

Bill,
The rubber or silicone rubber respirators that can be equipped with cartridges will protect you against the solvent vapors and the fiberglass particles. They generally sell in the hardware stores for $30. The trick is getting the correct cartridges for the respirator. For polyester resin, the main concern are the solvent vapors, in which case you need a cartridge labeled for protection against "Organic Vapors". These are generally the most common ones sold anyway. For fiberglass particles you need to equip the cartridge with a prefilter that is good for protection against particulates. These come labeled, most commonly, N95, N100, P95, or P100. Any of these listings will be fine for fiberglass. You can usually find in the hardware stores, respirators with cartridges that simultaneously protect against both organic vapors and particulates. They will have the N95 ... plus Organic Vapor labeling right on the box. They are sometimes sold as "Spray Painting" respirators.
Respirators equipped with cartridges that have yellow labels are meant for protection against acid gases and vapors. This type of protection is not necessary for polyester resin work and just adds extra cost to the respirator cartridge.

I hoped this discussion helped and was not too long winded. If you have any questions, just call or email me, and I can guide you further.
Jack

Thanks for the info- I've been using more and more chemicals and want to make sure ............... ahh



oh yeah, that I dont mess myself up too much. My fingers have split open using MEK, and stupid me didn't realize you absorb the stuff through your skin too.

It was really neat finding some of theold post with a wealth of information.

Thanks for the 411 on the mask- whats the shelf life? One use for the cartridges or multiple use??
Bill

The usage life of an organic vapor cartridge is approximately 8 hrs for styrene vapors. It is less in very high humidity. In between uses, store the cartridges in a zip loc bag and that will keep the degradation from humidity to a minimum.