Panga 25 bottom panels not conforming

Panga25 · Post by **Panga25** » Mon Dec 19, 2005 11:29 pm

All, I'm having difficulty in getting the bottom panels for the Panga 25 to conform to Frame A. For a point of reference, I'm looking at a situation similar to Jas':http://gallery.bateau2.comalbums/userpi ... CF0041.jpg
I've kerfed the bottom panels similar to the way Jas kerfed those on his Panga 20.
I'd like any insight into getting from the picture above to something similar to:
http://gallery.bateau2.comalbums/userpi ... el-ply.jpg

Thanks.

JimW · Post by **JimW** » Tue Dec 20, 2005 10:28 am

You are forcing things. I see a row of fasteners aft holding the bottom to the aft frames. I see clamps forward with a "wrinkle" in between. Loosen everything back up and loosely tie the keel with cable ties. Stick some scraps in between the panels to force gaps. Keep everything loose. Don't force the hull down on the frames until last step after it appears to be "squared up" well. That's how I handled it. I did have to loosen and re tie at least once.

Post by **jacquesmm** » Tue Dec 20, 2005 11:00 am

I agree with Jim. I see too much pressure on that panel. Let if float.
I would not look too much at the shape at frame A until the side panels are in place, two sides.
Even then, with different types of plywood and humidity, there maybe gaps up to 1/2" there. What count is a fair hull. Right now your panel is not fair because there are too many clamps and fasteners.

tech_support · Post by **tech_support** » Tue Dec 20, 2005 11:03 am

Jim, Those pictures are from the panga 20 , not the one the PG25 he is working on. I guess he using them as a reference.

Mark, could you please post some pictures of the boat? It helps a lot. If you cannot post them for some reason, email them to me and I will do it - so we can all see.

Joel

JASmine · Post by **JASmine** » Tue Dec 20, 2005 4:48 pm

Gentleman....as the owner of the aforementioned 'bad-way-to-do-it' pictures, I can assure you I understand the nature of "let-it-float" and the need for a fair hull shape. I tried many different techniques including the ones you just suggested before resulting to force. The picture in question was part of the learning process along the way..obviously wrinkles are BAD. You also may recall that Dynamo had to 'split' his bow pieces to get his to take shape. While I'm not a designer or expert in woodworking, I believe this bow contour is not likely without kerfs and some forcing. Perhaps if Jacques added the actual kerfing lines to the plans, these design lines would be better than my guesses and less force would be required. I felt at that stage that whatever produced a natural fair hull was worth trying....

Post by **jacquesmm** » Tue Dec 20, 2005 6:41 pm

Nothing wrong with kerfing or even cutting slits. This does not weaken the boat in our construction method.
A few longitudinal slits seem to work better than kerfing across.
We show it on the plans for the CS23/25 and it is a good idea to show them also on the Pangas. Thank for the suggestion.
If I remember well, once Jazmine did cut his slits, he could easily shape the bow around the frame.

Panga25 · Post by **Panga25** » Tue Dec 20, 2005 11:32 pm

I've posted some pics of the situation. I cut quite a few kerfs on the inside of the front 1/3 of the bottom panels. Most are 3 inches apart, sweeping aft from the centerline, with about a 45 degree sweep. On one of the pics, you'll notice what appear to be kerfs going in two different directions. Before cutting the kerfs, I drew them going in the wrong direction. At this point I'm off considerably on Frame A. I'm hoping to get a closer fit prior to attaching the side panels (at that point it will be very difficult to get access underneath the boat). In general, the panels don't appear to be distorted, it's just that I don't see how I'm going to get them close to Frame A without distorting them. If I go down the path of slitting the panels, going from bow to stern, any thoughts on where to start?

FLYonWALL9 · Post by **FLYonWALL9** » Wed Dec 21, 2005 12:48 am

I think if it were me at the point you are now seeing what I see; I would cut those cable ties and have about a 2" gap between your panels. pull about 1/4" in them from back to front and let it sit and conform. Then walk the stitches again. With our weather here thats what I would do, dry and cold 34deg at night or so. Just remember gaps are ok even good so don't try and pull those ties so your panels meet and see what happens

JimW · Post by **JimW** » Wed Dec 21, 2005 10:23 am

My C19 never really reached the camber of the frames just forward of amidships. That was the "crunch" spot for the C19. Trying to have bottom camber at the same point the hull bottoms were twisting and curving up to the bow. It had to twist and curve up so the camber suffered a little and frames had deeper fillets at the keel and chine areas. Get it as close as possible and fair then do like Larry the cable guy and "Get 'er done". I would add kerf cuts if I had this happen again.

JASmine · Post by **JASmine** » Wed Dec 21, 2005 10:30 am

Mark...I feel your pain!!..your pics take me back to when I was struggling with exactly the same problems. I also understand your dilemma about attaching the side panels and not having any way to then pull the panels to the A and B station shapes. My only recommendation is to do it whatever way seems to work for you...you know what you want in the end so try a few things. That's how Dynamo and I got through it.

I'm not familiar with the effect of cutting the slits but why not make a short test panel out of cheap ply and try it??

Good luck and keep asking...maybe I can help.

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