I know this is an old question, but I'm wondering about the best way to fill holes and gaps in my Pocket Cruiser prior to fiberglassing. In the Stevenson's Weekender DVD, joints, gaps and screws are filled with Bondo, but I get the impression that Bondo can weaken over time and that most people prefer epoxy fillers.
If that's the case, my question is this: What kind of epoxy filler should I use? Specifically, what brands do you recommend? I know the topic of epoxy brands was recently discussed, but I'm wondering if the kind of epoxy used as a filler is different from the kind used when fiberglassing the hull. Remember, I'm a complete beginner and have never used anything but hardware store brand epoxy (usually to fix broken plates and the like), so I'm mystified by epoxy in general. I'm many steps away from fiberglassing, but I am about to attach the sides and I want to fill the holes and voids in the cabin area before they are too hard to reach.
Use the same brand of epoxy that you used for everything else. Use a mixture of micro balloons or Qcells and a little silica (to stiffen the mix). Mash it into the hole with a putty knife, plastic applicator or some prefer to squirt it in with a syringe or squeeze bottle. I find squirting it in, with a thick mixture is too much trouble, so I use the smash and goo technique.
Paul, Thanks! I'll follow the advice provided on the previous thread about brands. Duckworks sells an epoxy kit that includes "wood flour" as the thickener. Would that work?
Paul, You can make your own using a belt sander and a peice of wood of the kind you will be making the fillets or glueing together.
I can't remember the kind of expoxy that I used to make my Whitehall, but I got it here:
This gentelman is very good at working with old boats and sells and ships epoxy. I know it is a major brand that he carries, but it is not West. I had no problems using it.
Here is his link...
http://www.cedartreeinc.com/
His name is Paul. He is very helpful.
Tom, Thanks for the recommendation. One more question: Should I buy slow, medium or fast hardener? I don't know how slow the "slow" is, or how fast the "fast" is.
In my earlier post, I observed that lots of people reject Bondo as a filler, but is there anyone who feels that it is acceptable for a boat that won't live in the water and doesn't need to outlive the builder, especially since the builder is already thinking about the *next* boat he wants to build?
Cedartree sells MAS epoxy, which is pretty expensive stuff at $70 a gallon, plus pumps.
Bondo has a number of issues with it's use on a boat. It absorbs moisture, which will cause it to swell up (not good under paint to see bumps). It doesn't like vibration and has a tendency to "circle out", which means it slowly loosens, a circle appears first, then a circular crack, then it falls out of the hole. Since it's polyester, it doesn't stick very well to epoxy coated surfaces (nor much else for that mater). It also likes to shrink when it dries, so when you think you have something perfectly smooth, give it a week and it's not anymore. This should be enough to make you reconsider Bondo. Considering the physical amount of filler you need to fill holes (a few ounces), it seems like false economy to use the stuff.
I've dug enough of this stuff out of boats to tell you it doesn't last very long. So, if you don't mind repainting every few years, because all your fastener holes have popped their "cork" then go for it. This of course assumes moisture didn't get inside the faster hole it was covering and cause other issues like rot.
Ok, ok. I'm convinced. In the Stevenson's DVD, they spread Bondo over every seam and seem to use lots of it. I don't know how much epoxy I will need to fill all the holes and cover the seams of the Pocket Cruiser, but it sounds like a good investment.
The only kind that Paul at Cedar Tree sold me was Medium for most things. For warm weather application he told me to go with the slow. I never tried to get more than one application done in a day.
I liked the slow, because it gave me some time to get the whole boat and cloth wetted in one shot.
Sounds like medium or slow is the way to go--maybe both depending on the weather? So many decisions...
Paul: bateau.com has an excellent chart listing open times for various hardeners in epoxy indexed to temperature. I live in Wisconsin where summertime temperatures range from 60 to 95 degrees. I just purchased 3 gallons with medium hardener, 3 gallons with slow hardener, and 1-1/2 gallons with fast hardener. This is for my Weekender. I should be able to "mix and match" hardeners for any temperature! Hope this helps.
Dave