Galasport CHOP SHOP 4m slalom boat alteration question

[poetry_heckler]

I picked up a Galasport Pyrog for super cheap and I want to make it into a SPyrog, a Short Pyrog.

I'm not interested in racing under any regulations, so I am going to chop the wings off and take 12" - 18" off the stern. I think those are pretty straightforward modifications.

What I need help with is taking a foot off the front end. I've come up with a few thoughts, but I'd like to hear from the group if anyone has experience doing this or just has extra harebrained ideas leaking out from their ears.

This thing is Kevlar and weighs about as much as two loaves of bread. It has several repairs, so it's not winning any beauty contests as it is.

I don't mind paddling a frankenboat so long as it's interesting and fun. And failure is always an option.

Let me know what you think.

ML

[wildwaterc2]

I can tell you what I did .

My first cut was on a beat Fanatic C1. I figured where I wanted to cut off each end, and just cut it off, all the way around. I then shaped some foam to the shape I wanted, and laid up cloth (fiberglass and kevlar) over that, then sanded. The rear did well as cut with about 18" cut off. On the front, the transition to the hull was a little abrupt and made some extra spray, so I had to grind down that transition some and reshape it and re-glass. None of this was super pretty, but it gave me a lot of shape flexibility, and the boat is a blast and does what I was seeking. And, it was easy to change the bow shape. I skipped end pours on this boat.

When I wanted to very neatly shorten the stern of a Grokshark that was in great condition, I took a different approach. On it, I cut off the hull where I wanted, but left the deck a little longer. Then, I shaped foam for the new part of the hull, and then laid up a transition piece over the foam - I made this piece of multiple layers of fiberglass. I then removed that fiberglass piece, cleaned the foam out, and then glassed that transition piece into the hull, with layers of glass and kevlar over it, and then finished any trimming of the deck to match the transition piece. I then did an end pour inside the stern since on a C2 it can take a beating and I wanted a good anchor spot for a new grabloop. This came out really well and looks nice.

If I was to do it again, I'd do it like on he Grokshark which is to leave some extra deck in place to make the transition to the slightly shorter hull - I think that comes out better.

I did not want to mess with chopping height at the seam or anything - just wanted to rid myself of the pointy ends. Once you start chopping seams it is a different level of complexity.

[poetry_heckler]

That's along the lines of one approach I was thinking, except to make a closed-cell form for the bow and actually glass it into the boat in the process.

Maybe that's a crummy long-term situation, I don't know. But yeah, cutting the deck close to the desired shape and then cutting the hull back a bit to make room for the transition seems like a good approach.

[poetry_heckler]

Thanks for the response.

[clt_capt]

If you will be using epoxy, you can use the pink EPS foam - shapes easier than minicel, won't dissolve in epoxy. Also won't weigh as much

[edg]

I couldn't find it on their site, but River Elf used to have a fantastic PDF guide to cutting down slalom boats. I used it, in part, for my "Tang" -- an Estanguet Grouin cut down to 3.5 meters (and later given the Speed wing treatment on the back deck). Essentially, as I recall, you cut the top deck 4-6 inches longer than the bottom, and round off the front corners. The bottom deck cut is left square. The gap is filled with spray foam, which is sanded to a smooth contour when dry. Then composite is laid over the foam to create the new shape. Finally, new seam tape is laid over the new bow/stern shape.