Another boat

[Lootas1]

Okay, it is just a 7 1/2 fiberglass dinghy and it was free so I guess it hardly counts as a boat. However, I think it is worth every cent I paid for it. Got a split in the side about a foot long and, since I just got it, I'm anxious to fix it up. Have messed with a fair amount of fiberglass over the past half century but forgot most of what I once knew. My question today is how warm is warm enough to repair the hull? I don't have any heat I can put on it. Don't figure it is something I would want to mess with until it warms up a bit but say 50 degrees? Could I just increase the hardener until it will kick in say 15-20 minutes? Or do I really need to wait until spring?:Cold1::Cold1:Jerry

[Tim_Mattson]

Jerry,
You can tarp it over with a light or safe heater to pre-heat the hull once prepped.Keep the epoxy material warm and mix normally and you should be ok.
Upping the hardener may make a weaker repair if it gets too hot.
A small space heater or light while it dries will get it hard overnite.
A cardboard box could be used to confine heat to the repaired area as well,just don`t start a bonfire!
Faster cures mean weaker strength.....
Final tip on blending the patch,try tearing chop strand instead of cutting with scissors.Let the Hairs lay however they want reaching out from the seam of crack.A Cloth Band-aid can go on later or right on as it tacks up so you can squeegie the epoxy smoother.
Also good to do both sides of hull so strength is balanced.
Some Twin hulls have double glass on one side for davits used on Tip-up stored hulls.
TimM

[Lootas1]

Thanks Tim. I was wondering if loading the resin with hardener would have a negative affect. Guess one of these days, I'll pull the truck out of the garage and open door and window so I don't drive Becky out of the house and put a tarp and heater over the dinghy. Suppose I'll need to patch both inside and out. Are you suggesting a longer patch and both port and starboard on either side to make the dinghy stronger? Suppose I should think about some foam under the bow seat so it doesn't go to the bottom if I tow it too fast and flip it. I'm still thinking of that little Mid-jet ob down in Oregon. It seems so cool. Hoping when he said it doesn't run, he was talking about the Tehcumseh or Briggs and Stratton motor and not the lower stuff.
Not that I can't row from boat to shore and back.

[bham-rick]

Hot house

I just laid a couple boards across the boat and had a small space heater inside and then laid a couple blankets over the top and a few other boards to weigh it down, Just like Tim described . Worked really good . If you put in too much hardener it takes away some of the strength and makes it brittle (so I've been told )

[Lootas1]

Oh, yah, where were you Tuesday when I hauled a nice big quilt to the dump and paid good money to get rid of it? Thanks. Must have another quilt around here somewhere.

[McSkagit Tim Jones]

Polyester or Epoxy?

Jerry,
I presume you are repairing with polyester resin. I'm beginning to prefer repairing with epoxy, although fiberglass mat doesn't wet out well with epoxy. Cloth without the sizing in it works fine.

Preheating your resin (polyester or epoxy) is critical this time of year. I use a crock pot I got at a garage sale for 50 cents. Careful not to get it too hot, especially polyester.

Working with epoxy, I would occasionally have some mixed left over and would stick it in the freezer thinking that it wouldn't kick and I could use it later. Next morning I'd pull it out of the freezer and it was hard as a rock. Seems once epoxy starts to cure, there is no stopping it....

Bad resin (Low styrene)
I had a problem a year or so back with a batch of polyester laminating resin.
I would catalyze it the same as I had for years, but it wouldn't kick. So I put a heat lamp on it and still no kick. Moved the heat lamp closer....an hour later I noticing print-through on the hull!! Crap! In the end I ripped it out and started over. Catalyzed with twice as much catalyst. Still didn't kick! Bought a new gallon of resin and worked fine...... Beware of "low styrene" polyester resin!

My two cents worth...