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  #16  
Old 06-13-2010, 06:08 PM
CatBuilder CatBuilder is offline
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I only have one small bit to add since, while I haven't begun, I do understand the hull construction steps on these boats.

I would fill the space without epoxy full of the exact same epoxy you have everywhere else. Why?

When you bend the hull sides up to get them in the deck jig, if you have the same plywood everywhere, with the same consistency of epoxy between them, you will have a more even distribution of the stresses. If one part of the hull bends just a little differently from the other, not only might you go out of fair, but you might also wind up with a huge stress point.

Just a thought from a guy about to start one of these.

Is this 3mm Okoume that isn't bending well??? Or did you go for 4mm?
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  #17  
Old 06-13-2010, 06:33 PM
apex1
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Quote:
Originally Posted by CatBuilder View Post
I only have one small bit to add since, while I haven't begun, I do understand the hull construction steps on these boats.

I would fill the space without epoxy full of the exact same epoxy you have everywhere else. Why?
Have not got that, sorry.

But, again, I am not familiar with the method.

And 3mm Okoumee bends very well.

Regards
Richard
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  #18  
Old 06-14-2010, 01:35 PM
CatBuilder CatBuilder is offline
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Quote:
Originally Posted by apex1 View Post
Have not got that, sorry.

But, again, I am not familiar with the method.

And 3mm Okoumee bends very well.

Regards
Richard
Maybe I didn't word it clearly:

I was suggesting that he use the same materials throughout the hull because it will be bent.

If you bend something and it is made of two different materials, you will have stress points that would not exist if it were made of one material.

So... I was saying he should try to create a very uniform, homogeneous panel and use the very same materials throughout (same epoxy, probably not 5200).
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  #19  
Old 06-14-2010, 02:42 PM
apex1
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Thanks,

now I have the idea.
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  #20  
Old 06-15-2010, 05:50 PM
Charly Charly is offline
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Thanks for the inputs, you guys. I guess I will wait till I do the cut out of the hull profiles. I already have the flat surface panel lofted, but I want to wait till all the hull laminating is completed and cur them all in one go. This and any other voids may be opened up at that time by the saw.

Here are a few pics of the second session.
Attached Thumbnails
Kurt Hughes Daycharter 36-catamaran-port-hull-2-001.jpg  Kurt Hughes Daycharter 36-catamaran-port-hull-2-002.jpg  Kurt Hughes Daycharter 36-catamaran-port-hull-2-004.jpg  

Kurt Hughes Daycharter 36-catamaran-port-hull-2-005.jpg  Kurt Hughes Daycharter 36-catamaran-port-hull-2-008.jpg  
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  #21  
Old 06-22-2010, 08:01 PM
Charly Charly is offline
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A couple of photos from yesterday's session, joining longitudinal scarfs to form 8x7 panels and bagging a stack of them to the floor. These fifteen panels will eventually be the starboard side of one of the hulls.

The close up is of the 1088 stamp on a 3mm sheet of ply. Is this a "normal" stamp? I was thinking about what mark775 said about standard claims. This ply came from Boulter, which is a reputable outfit. Is this stamp unique to the maunfacturer?
Attached Thumbnails
Kurt Hughes Daycharter 36-catamaran-bagging-panels-001.jpg  Kurt Hughes Daycharter 36-catamaran-bagging-panels-002.jpg  Kurt Hughes Daycharter 36-catamaran-bagging-panels-003.jpg  

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  #22  
Old 06-23-2010, 08:40 AM
CatBuilder CatBuilder is offline
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Excellent work, Charly!!

These pictures are getting me very excited. I'm struggling with people/delays on getting my building put up. Should be up next week, then I can start, too.

So is that BS1088 3mm or 4mm? I seem to have trouble finding 3mm and 4mm supposedly is a little stiff for bending. What did you choose?
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  #23  
Old 06-23-2010, 07:21 PM
Charly Charly is offline
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Hey Catbuilder,
It is 3mm. http://www.boulterplywood.com/

Notice that their ad says that the 3mm is to 6566.. but the stamp on my wood that they sent says 1088. I'm still not sure what that means. (I guess I could pick up the phone and ask em :-)) I did measure it though, it is 3ply, 3mm.
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  #24  
Old 06-25-2010, 08:24 PM
uncookedlentil uncookedlentil is offline
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I've got four Kurt Hughes boats in my past, keep your questions direct and he's pretty helpful to his customers.

I've repaired old cold molded hulls by standing void areas on edge, drilled holes top and bottom of void, use flat bottom drill and Try to not punch thru middle ply. now thefun, use a curved dentist syringe and inject epoxy in the topholes until it weeps out the bottom on both sides, plug bottom holes with filet grade epoxy.

Now grab your predrilled, plastic covered 1x2 and deck screw from outside to a plastic protected backing stick, all on the horizontal of course.

estimate volume of void minus clamping, continue filling from the top, adding clamps as you go, until epoxy oozes from top holes, then finish clamping.

It takes less time to do than to describe it but be sure to use slow hardener
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  #25  
Old 06-26-2010, 03:18 PM
Charly Charly is offline
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Thanks, Lentil. Cool trick.

I am wondering if I have this void because of the plywood being too stiff for the biaxial mold, or if I am doing something wrong. I checked my height of the individual mold stations, and the straightness and squareness of the mold, etc, and it seems OK to me. Did you have any similiar problems?
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  #26  
Old 06-26-2010, 06:28 PM
uncookedlentil uncookedlentil is offline
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hows your vacuum performance and distribution? shouldn't be able to pick up on a wrinkle during bagging.

if you're really curious do a dry run

i suspect your mold might have a tch too much camberfrom end to end for the stiffness of your ply, assuming that bagging procedures are totally in order

it's half art and half science

just do all skins identical so that the foldups are identical

repair voids before folding, the sterns take a fair amount of torqueing to develop fullness
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  #27  
Old 06-27-2010, 06:07 PM
Charly Charly is offline
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Quote:
Originally Posted by uncookedlentil View Post
hows your vacuum performance and distribution? shouldn't be able to pick up on a wrinkle during bagging.

if you're really curious do a dry run

i suspect your mold might have a tch too much camberfrom end to end for the stiffness of your ply, assuming that bagging procedures are totally in order

it's half art and half science

just do all skins identical so that the foldups are identical

repair voids before folding, the sterns take a fair amount of torqueing to develop fullness
I can't pick up a wrinkle. It seems to be sucking down pretty good.

I did my third hull section last night and I believe that it is my best one so far- I havent found any voids yet. It feels and sounds pretty solid.

There is a photo in the construction manual that shows an end shot of the form with some sheets of ply on it, ready for bagging. The ply rides up above the form a few inches right about the turn of the bilge. Mine does the same thing, and this area is the place that I am having the voids. Last night I made an extra effort to manually force down and smooth the sheets out as they were going on, and I think it may have made a difference. The final panel still rides up on the form, but at least the individual sheets are compressed together better.
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  #28  
Old 06-28-2010, 09:32 AM
uncookedlentil uncookedlentil is offline
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excellent on the void avoidance. I can see a lot tighter bilge curve on your mold then boats I folded in the past, should help with final displacement

hull pattern needs to be placed as consistent as possible on all 4 sides

Last edited by uncookedlentil : 06-29-2010 at 03:26 PM. Reason: edited for clarity
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  #29  
Old 07-21-2010, 03:07 PM
Charly Charly is offline
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Cut-out time!

This the first one, until I can get some help moving the beasts around and cut the rest.
Attached Thumbnails
Kurt Hughes Daycharter 36-stb-cutout-001.jpg  Kurt Hughes Daycharter 36-stb-cutout-004.jpg  Kurt Hughes Daycharter 36-stb-cutout-006.jpg  

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  #30  
Old 07-21-2010, 03:15 PM
CatBuilder CatBuilder is offline
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Nice job, Charly!! You are certainly a hard man to play catch up with. It's like looking into the future! (about a month into the future)

Looks exactly right, like everything I've seen in the videos and plans. I like that you located the stringers and stitching points with the flat panel profile ahead of time. Good time savings.

COOL!
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