BYYB Forums

ok guys, I've run into my first problem.
After reading a whole lot of posts I want to make sure I'm understanding correctly, sounds like the recommend gluing method is to use epoxy and in some cases filler.

I'm getting ready to glue my keel and hull bottom together here soon I was going to use Weldwood Plastic Resin Glue per video but figure I try epoxy.  Here's my problem other then using the small dual tub kits for minor repairs around the house I haven't used epoxy a whole lot.

1.  when do I add filler, only when I know there are large gaps or should I also use filler when putting keel boards together to help avoid likely gaps?
2.  where can I get epoxy and filler?  are there different types, is one better then the other.
      I understand a little about the different types of hardeners, but additional info on this would help

I was looking at the glen-l site and saw a couple of different types but not sure if this is best/cheapest place to get it at
    https://www.boatdesigns.com/Poxy-Grip/products/287/
    https://www.boatdesigns.com/Fillers/products/282/

Raka is a pretty popular epoxy,I used it on my first boat and was impressed with the strength factor,tho a bit thick for my liking
http://www.raka.com/

I am currently using epoxy from Aeromarine which is much thinner.

http://www.aeromarineproducts.com/

Both sites carry all the accessories,Fillers,cloth etc .

As for usage,and what is best,I'll let others chime in.

Bob

Marinepoxy from bateau.com is the cheapest of all the marine grade, non-blushing (if there is such a thing), good quality goo's going.

Epoxy is used as a coating (straight) and as a adhesive. As an adhesive, it's almost always mixed with something to improve it's mechanical properties.

Log onto www.wsetsystem.co and www.systemsthree.com and download their user's guides. These will nurse you through the basics. Don't get distracted by the product types, stick with basic resin and the hardener(s) you need for your environment. Buy fillers in bulk, you'll use lots of it. The most common are silica, which is used to control viscosity and stiffness, wood flour, which makes a glue and can help hide blemishes under varnish, milled fibers (not chopped) which improves bond strength on different surfaces, especially on 'glass fabrics, cotton flock another strengthening agent and the light stuff for fairing, like micro balloons and Q-cells.

Paul,  I have been using silica for glueing. Results have been good until now. Im ok with this or should I switch to the wood flour?

That's a difficult question to answer Carlos. It's depends on how thick you made it and/or "procedural" issues. There are lots of things that can screw up a bond and determining if it was the silica or something else can be difficult to say the least.

I always tell folks to download the user's guides from the two major formulators and then work from there. The reason is simple, successful epoxy work is nothing more then using good technique. The only way to get this without having goo on your fingers, is to read up on the subject. There are some videos on the web, but many of these have procedural mistakes and bad technique, so you're best with the pros. Joel over a Bateau.com has some good videos now, worth looking over so you can see how some of the tasks are preformed.

To answer your question, it's very rare for me to have just one filler material in a batch of thickened goo. Silica is used to thicken epoxy up so it doesn't sag, but it can easy be over used, making the epoxy weak and brittle. If you use too much, the compressive strength will be impressive, but it will snap like a twig in a bending moment. This is why I use multiple filler materials, each suited for the job at hand. A typical glue would have some milled fibers, wood flour and silica to thicken it up. I might add some talc if I have to sand it after I'm done or I might use a "combo" package like West 405 (which is wood flour, cotton flock and silica). All really depends on what I'm gluing. I have mixed up combinations that I commonly use, already in a can waiting for me. I buy bulk materials and pre-mix, so it's easy come goo in hand time. Most folks needn't bother with this, as they'll never do enough epoxy work to warrant the trouble.

Bob and Paul thanks for the info and links, Paul the links to the how to/user guides are just what I need, thanks big time.

Carlos thanks good question (I probably wouldn't have thought of that one for a while  )

I would add that after trying fast hardeners and slow hardeners I vastly prefer slow hardeners.  Others may differ but the added pot life and working time mean more to me then the few hours savings that fast hardeners give.  I usually get 45 minutes pot life using slow hardeners and only about half that with the fast.  I bought my first gallon of marine epoxy resin and half gallon of hardener from: http://www.duckworksbbs.com/supplies.htm.  I have since bought a couple of gallons of West System 105 epoxy from here: http://www.jamestowndistributors.com/use...poxy+Resin

I used a mix of silica and wood flour for most glue ups and straight epoxy only for coatings.  I mix in the silica first since it is so powdery and then the wood flour.  I ratio them one part silica and 2 parts wood flour.  I usually go for a consistency of light peanut butter.  This is for glue ups.  Foe bondoing I use micro balloons mixed in straight eposy so it sands easier.  It all may sound complex but you will get a technique you like and it will just seem natural.

Terry,  good point on the hardeners. But, living on a tropical island, with winters in the low eighties and summers in the high nineties, I learned the hard way that the fast hardeners are almost a waste of money and the slow ones give about twenty minutes of pot life. My mixes have to be kept small and I have to move fast.  Is there way to extend pot life in my mixes without sacrificing strength?

I started my weekender with West System.  That got too expensive pretty fast and I switched to Marinepoxy.  I loved it.  I have only bought the fast hardener.  Up here if I lay something up in the morning, the goo hasn't gone off by late afternoon usually.  With the fast hardener, it is a full 24 hrs before I could scrape off the lumps and at least a couple days before it is completely hard.  I don't know exactly what the pot life is, because I have never gotten to the point where I had a bunch left in the cup even if I screw around with the layup.  The up side of this is that I can laminate up things if I just keep the shop above 40 degrees.  The marinepoxy is fairly pliable when it is green and you can save yourself a lot of sanding if you scrape off the excess high spots with a piece of cut glass.  I get mine from my local hardware store where they cut replacement glass.

Up here in the frozen north, it is still possible to build boats in the dead of winter if you can get just a bit of warmth in the shop and keep it for a while. 

Al

I, too, used Marinepoxy and was very happy with the results.  Price is right too!  For gluing, I thickened the goo with a 50/50 mix of silica and wood flour (by volume).  It I need the glue to stand up to gravity (vertical surface) using more silica helps.  Thicken to peanutbutter consistency.

Dave