BYYB Forums

    Hi;  Franny & I started building our Weekender yesterday and got all the port & starboard pieces marked and laid out before it rained us out, we have a canvas garage being delivered tomorrow and should help the building here in New England.  The next step is cutting and putting pieces together so any advice on adhesive would be helpfull.

                  Alan & Fran

Some days it seems that there are as many choices for adhesives out there as there are people.

Hands down - without argument, the best adhesive to use is an epoxy thickened with silica.  It's incredibly strong, impossible to sand and rather expensive.  Different fillers such as micro-balloons or wood flour are slightly less strong, but still provide a strong bond.  On the "con" side, other than being expensive, you need to protect yourself from sanding dust otherwise it is possible to develop the rather rare alergies that some people get.

Following that choice are some of the polyurethane adhesives.  These include products like TiteBond and I believe, Gorilla Glue, and my own favourite PL Premium construction adhesive.  Some of the variations of these adhesives are not "waterproof" - a standard that requires the adhesive to stand up when subjected to boiling water.  If your sailing plans do not include boiling water, these will work for you.  One of the features of these adhesives for a wood-butcher like myself is that they expand as they cure, filling in some of my less than perfect joinery.  Again, wear gloves when applying these adhesives as they will stain skin and the PL Premium at least looks like you have dried boogers all over you.

Plastic resin glues like the Stevensons recommend can also work well, but are now hard to find and aren't as easy to apply as some of the more modern adhesives.

Hope that helps.

Having built 6 boats in the last 8 yrs I can speak with good authority about epoxy poisoning. This last boat, a 20 ft. by 9 ft. houseboat glassed and epoxied finally showed me that I did not take care to cover up. I broke out on my arms, finger tips, legs, eyes, and ITCH.....It took 8 or 9 mos. to calm down. I WEAR GLOVES EVERY TIME I MIX. I put a blower pointed at me every time. I clean up with vinegar NOT ACETONE at worst I use lacquer thinner. Acetone and epoxy is like a trap door through your skin into your body. 3 yrs later I still have 3 quarter sized sores on my left leg and 1 on my right leg.
It is after all why I believe in using plastic resin glue as much as possible works for me. Plus it is still available at good lumber stores and way cheaper than epoxy. You still need to cover the hull with glass and epoxy but you can cut your exposure way down. I still don't understand why the manufactures don't give good information about this. Here is a site I found that will help anyone using epoxy to understand what they are playing with. Good luck, Warren                                                                                        http://www.fram.nl/workshop/controlled_v...llergy.htm

Epoxy as you might have guessed, is the hands down industry favorite and for many good reasons. It's cost can be mitigated to a degree, when you think about what it does. It's more then just a glue. It's a sealer, a protectent, a glue, a fairing compound, a fastener/hardware bonder and it's used to set the 'glass cloth that protects the hull, oh did I mention it's a water proofer too. Taken in this light it's a hell of a lot more then just a glue. You can't do any of these things, except glue with PVA's (like TiteBond) or PU's (like Gorilla glue) or urea formaldehyde glues. These are just glues and can't compete with all that epoxy will do for a project.

So, yep, it's not the cheapest stuff going, but it's also not just a glue either. A good source for low cost, non-blushing epoxy if Bateau.com. Their Marinepoxy comes in three hardener rates and works well. A Weekender will require about 5 gallons, if you're neat about it's use. This is a few hundred bucks of goo, but remember this stuff does everything, coats, seals, sticks your 'glass down, water proofs, makes fillets and glues too. If you order from Bateau, give Joel a call and tell him I sent you, he might just let you have a builder's discount. He's a nice guy and quite helpful.

Raka is a popular brand here, though I don't like it much, it's too runny for me, which makes me use more then necessary.

Epoxy is inert when cured. Naturally you don't want to breath in sanding particulates and you should avoid eating, bathing and rubbing the stuff in your eyes. As a liquid the hardeners causes most of the difficulties with people. The non-blushing formulations are much less likely to cause a reaction with you. Those that do develop an allergic reaction to epoxy do so for one of two reasons; they were bathing in it or they are sensitive to alkyne substances. Some folks just seem much more prone to this than others. I've been using epoxies (some quite unrefined) since the 1970's and no ill effects, though I do notice a slight reaction around some brands now. I know others that can't even walk into my shop if epoxy is curing without breaking into a rash.

Work with ventilation, wear gloves and use a dust mask when sanding. Keep the liquid stuff off you, it's cumulative poison, so limit exposure and you're good to go.

The listed link to "Epoxy Sensitivity" is full of myths with some good information intermixed. It even has one of my old posts (2002) about toxicity. If you take all that text to heart, you'd never go outside for fear of ambient epoxy particulates. The bottom line is some folks will get reactions, others seemingly can swim in the stuff with no ill effects. If you're a "sensitive skin" guy, then take extra care.

One in three people are sensitive enough that epoxy is something they should not handle without taking measures to prevent contact.  That doesn't mean that 67% of us can bath in it and anyone getting it in a sensitive place, like eyes, ears or privates (don't ask it was a friend and he had been drinking), will regret it.  For most of the sensitive 33% group it takes time and multiple exposures to start the reactions.  I didn't want to find out that I was sensitive so when I built my boat I made sure to always use gloves, had adequate ventilation, cleaned up with vinegar and always removed the gloves before stepping outside to recycle any beer.  So far so good and after 2 years of using it no ill effects.

I would suggest you use slow hardener until you get proficient with it.  I tried fast hardener and had a couple of small batches that set up while I was brushing it on.  I don't see much advantage to faster  hardeners but others are probably better at getting it just how they like it quicker and may disagree.  I use paper cereal bowls for small batches.  They are open enough that it doesn't get to thick and go thermal and have high enough edges I don't usually tip far enough to dribble epoxy down my arm when bent over applying it.  Mixing in wood flour, silica, graphite, aluminum and micro balloons is not difficult to get a handle on so don't worry if it sounds complex.

A quick, easy way to extend the life of a batch is to pour out your batch onto waxpaper or some plastic tarp so the depth is very shallow. This will double the use time. Terry started right away doing all the things I didn't do! I've been in the sign business all my life and sticking my hands in every paint and glue that came along. Not good. I'm still building and using epoxy but I'm careful and don't experience much difficulty any more.

      I like and have been using titebond 3.  I put my seat bases together with it and my mini nailer from harbor freight..  The bond is so strong that when I needed to redo a section the 2 pieces of wood were totaly bonded together, the only way I got it apart was ripping the underlying wood apart... 

      An example of strength for the glue would be when I glued a 2x2 against the lazerette wall to support the end of the seat.  I glued and screwed the piece to the wall and let it dry for 48 hrs then I took the screws out.  I tested the strength of the bond by standing on the piece of 2x2, it would not budge or flex at all, talk about strength,  I'm a believer..    I like using epoxy to, but this waterproof glue is so easy to use, no mixing,nothing. ;D

The problem with PVA's like TiteBond III is they can't be repaired or over coated with epoxy. It just doesn't like to stick to the stuff, so be careful what you use PVA's on. I use TiteBond III (which is just barely waterproof and not at all designed for immersion) on lots of stuff, but I'm very careful to keep the glue inside the joint only. It's also not rated as a structural adhesive, likely because of "joint creep".

I did a 6 month test of two sets of SYP blocks, one glued with epoxy with wood floor and one glued with titebond III. I left them in the dishwasher  for 6 months and hundreds of washes.  The wood and bonds were as solid after 6 months as the day they went in.  They were allowed to dry inbetween washings.  The one bad thing about the test might be no rot.  I am not sure rot could grow since the water used would have detergent for half the cycles?  I would consider using TBIII for suitable applications above the water line where constant vibration wasn't a concern but I used epoxy with fillers for 99% of the build on the boat.

    Has anyone tried attaching stingers to plywood with P1 Polyurethane Construction Adhesive and screws and then fiber glassing the stringers and feathering them into the plywood, the exterior would all be fiber glass of course, wouldn't this seal all of the structural points?  I believe this would speed up building time and cut cost of building a bit and the savings on the P1 over epoxy could be passed on to off set the cost of the BS 1088 marine plywood for those of us on budget.  ???

                      Alan & Fran