|
Tom Lathrop
|
 |
« Reply #75 on: February 07, 2007, 05:24:15 PM » |
|
After sitting in the cockpit today, I will modify my earlier statements a bit. I cannot see directly over the cabin but can see where I am going forward. Of course I am a bit taller than Graham. Vision would not be a problem.
|
|
|
|
|
Logged
|
|
|
|
|
Designer
|
|
« Reply #76 on: February 09, 2007, 09:08:06 AM » |
|
Yesterday we installed the mast step, glued up the rudder cheeks and Tom installed the epoxy soaked rope on the leading edge of the centerboard.
We have been held up for a couple of days waiting for the epoxy coating to cure enough to sand for painting, it was 31 degrees in the shop early this morning.
|
|
|
|
Logged
|
Graham
|
|
|
|
Designer
|
|
« Reply #77 on: February 09, 2007, 09:09:38 AM » |
|
Centerboard
|
|
|
|
Logged
|
Graham
|
|
|
|
Howard
|
|
« Reply #78 on: February 09, 2007, 12:45:53 PM » |
|
When you get around to pulling the wax paper off that CB, can you or Tom take some detailed photos of how that rope trick was done? I've heard of this many times, but have never seen it up close. Is the rope glued to the edge or in a groove? How much fairing next to it? How far do you wrap it around and how do you fair the ends. That sort of thing.
Looking very good....as we might expect from this particular team of builders.
|
|
|
|
|
Logged
|
Spindrift 10N #529, About Done
|
|
|
|
Tom Lathrop
|
|
« Reply #79 on: February 09, 2007, 07:18:30 PM » |
|
I never use wax paper with epoxy. Poly sheeting is far better in all respects. Wax paper wil stick to epoxy if it gets warm during the cure phase and is not nearly strong enough for this job.
A groove in the edge is not necessary. I make a flat that will allow the line selected to form the desired radius on the leading edge. I like soft braided dacron line best but nylon will work fine for the edge. We used 3/8" line here. After planing the edge, I drilled a hole on the upper end to fit the end of the line in. A notch was chiseled in the lower end of the board to allow the line to taper off.
The line is then coiled in a cup of epoxy and worked with a paddle to get the air bubbles out. Stick the line in the upper hole and hamer in a temporary nail because the line is going to be stretched as much as possible to hold it straight along the edge with a nail driven in the other end. Cut a strip of plastic sheet and wrap it over the edge as shown. Fix one end with staples driven through duct tape for reinforcement. Stretch the plastic toward the other end and staple that. Now pull the plastic down evenly on both sides and staple. The plastic sheet will make the soaked line smooth because you dont want to have to sand it, which is almost impossible anyway. You will generally need to fill some gaps with fairing mix after the plastic is removed and then sand that smooth.
This makes an almost indestructable edge on centerboards, rudders, paddles, stems and whatever. I don't think the Florida Bay flats will give it any trouble. I've been making these for about 20 years and never had one fail in any way.
|
|
|
|
|
Logged
|
|
|
|
|
Howard
|
|
« Reply #80 on: February 10, 2007, 05:39:11 AM » |
|
Ah yes.....that is plastic. I use wax paper to catch drips, but that is about all. Stretched like that, it would never work. Is that stretched tight enough to compress the rope into a pyramid shape or just to smooth the leading edge? Any thickeners in the epoxy? What wood was used to make the CB? Looks like western cedar. I assume you also cover the board....rope too....with xynole?
Also, having used a vacuum packer a few times, it is amazing how little suck is needed to pull a vacuum. I was thinking a person could coil the rope in the bottom of a plastic bucket just big enough to allow the full coil to lay flat on the bottom, fit the bucket with a lid of lexan....with a 1 inch hole drilled in it...then dump the epoxy on the rope, place the lid and hit it with a shop vac. You should suck nothing but air, and it should "boil" off any air instantly. Would void ALL the air in the rope and allow you to get to work before the epoxy heats up and gets "busy".
|
|
|
|
|
Logged
|
Spindrift 10N #529, About Done
|
|
|
|
lsearle
|
|
« Reply #81 on: February 10, 2007, 06:35:06 AM » |
|
We have been using exactly this method for 20 years to pull the bubbles out of two pack varnish in cold weather! then we heat the surface to about +5 over ambient and apply. Is there a " best " kind of rope to use? Is poly better than Nylon ?
|
|
|
|
|
Logged
|
Wet 'n' windy
|
|
|
|
Hirilondė
|
|
« Reply #82 on: February 10, 2007, 07:37:37 AM » |
|
The plastic sheet will make the soaked line smooth because you dont want to have to sand it, which is almost impossible anyway. Would vacuum bagging improve on this? Or do you think your stretching technique is quite sufficiant? |
|
|
|
|
Logged
|
Dave Finnegan
Pearson Renegade "Hirilondė"
Spindrift 9N # 521
The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.
Bertrand Russell
|
|
|
|
Tom Lathrop
|
|
« Reply #83 on: February 10, 2007, 08:01:56 AM » |
|
I think vacuum bagging is great when it is needed but would be an added complication here and might even be worse.
The best kind of line? All the synthetics are very tough so the decision rests on which one is easiest to use. I would not use polypropylene though. Braided line is more symetrical and make a smooth edge. The soft kind soaks up resin quicker. We used a nubby line because that is what we had at the time and time is limited but it needed more fairing with thickened epoxy than braided would have. All the lines I have used have taken up the epoxy well enough.
I have used this technique on the lead daggerboard of a 26' racing boat (larger line of course) and had the boat come to a complete stop after hitting an old engine block, or something like that, under power in our creek - no damage.
Try an experiment. Soak a short length of line in epoxy and let it cure. Try pummeling it with a hammer to see the toughness of it.
|
|
|
|
|
Logged
|
|
|
|
|
dstgean
|
|
« Reply #84 on: February 15, 2007, 06:21:01 PM » |
|
How's it coming?
Dan
|
|
|
|
|
Logged
|
|
|
|
|
Tom Lathrop
|
|
« Reply #85 on: February 15, 2007, 09:23:05 PM » |
|
One of us remembered to bring a camera today,so here are some latest photos. Time flies but still planing to be at the start on time. Maybe some warmer weather next week.
|
|
|
|
Logged
|
|
|
|
|
Garry
|
|
« Reply #86 on: February 16, 2007, 05:43:28 AM » |
|
Details, details. There is always so much to do after the basic hull and deck come to gether. Looking great.
Curious, what is the advantage to having the tiller pass through the opening in the stern rather than passing over the stern?
|
|
|
|
|
Logged
|
The adventure continues! or Begin...the rest is easy!
Birder 2
thinking of Core Sound 15 or 17
dreaming of Princess 28
sold Spindrift 11N, Pied Piper 28, Allied Princess 36 ketch
|
|
|
|
Tom Lathrop
|
|
« Reply #87 on: February 16, 2007, 07:08:13 AM » |
|
Details, details. There is always so much to do after the basic hull and deck come to gether. Looking great.
Curious, what is the advantage to having the tiller pass through the opening in the stern rather than passing over the stern? It helps keep the mizzen sheets from snagging on the rudder head when tacking or jibing. |
|
|
|
|
Logged
|
|
|
|
|
Designer
|
|
« Reply #88 on: February 16, 2007, 07:53:21 AM » |
|
I mainly ran the tiller through the transom to save weight.
You might find the spar tops interesting. The best strength to weight ratio we could find was thin wall birdsmouth wood with carbon braid on the outside. The mainmast top weighed 7# 3 ounces for 10' long and 3 1/4" dia. tapering to 2". We could find commercially made all carbon spars at just over 1# per foot.
|
|
|
|
|
Logged
|
Graham
|
|
|
|
Tom Lathrop
|
|
« Reply #89 on: February 16, 2007, 09:25:49 AM » |
|
I mainly ran the tiller through the transom to save weight.
I like my version better. Just for that, I'm going to sneak an extra teaspoon of epoxy into the mizzen mast top. |
|
|
|
|
Logged
|
|
|
|
|
January 24, 2003, 05:08:15 PM
