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Another Corsair 13

Posted: Fri May 06, 2005 8:57 pm
by richwink
Hi

I started this post in the "sail boats" category but will continue it in the proper category now.

Anyway got lots of work done since my last post! I now have all my cleats cut and ready for installation.

Also finished taping the inside of my boat and coated it with epoxy. I made a small mistake in that I did all the fillets first and then put the tape over the hardened fillets. This resulted in several of the fillets with air bubbles as I did them. To counter act this I pushed epoxy through the tape to displace the air. This worked in most areas however I am sure that the epoxy to tape ratio has been shot. I hope Jacque put a factor of safety called the amateur builder factor :lol:

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Next week I plan to glue on the cleats and flip the boat to fair, tape the seams and fibreglass the hull.

Couple of Problems/Ideas/Questions:

1) I have the metric drawings and they don't have a mast length on them? Planning to use aluminum pipe to start.
2) I am going to drill holes through the A and B frames to allow for oar storage into the bow section. Will also have to drill drainage holes for the inevitable water pentration. Does anyone have a better way to store oars on board?
3) I want to foam the boat to give it a positive bouyancy anyone have ideas on the best place and way to do this? I was thinking of opening up the middle seat area for some storage and foaming the front and back seat areas. Will probably foam the bow section partially.
4) I have seen several boats with frame sections cut out for access under seats and in the bow. What size of frame should I leave around the holes to minimize the effects of the holes?
5) I also want to cut a hole in the spray deck to use the area in the bow for storage of an anchor and rope... any ideas on how to prevent too much water from getting in there (hatch or seal?)

Corsair 13 Progress

Posted: Tue May 17, 2005 8:18 pm
by richwink
Hi

Been about 20 hours of "tool time" since my last post so I thought I would update you all.

Completed the rub rails and the cleats on the inside of the boat. Shaped the centerboard and have the rudder components all glued together. You can see the cleats and rub rails as well as the centerboard donw on the left. Used a handheld power planer which made quick work of the centerboard shaping. Needed to do some cleanup with the belt sander after though. I rented the tool which got me into a little trouble as I hogged off a little too much on one side. Will take better pics of the centerboard next time I am in the shop.

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Next Steps:

1. Glue in centerboard case and fair outer hull.
2. Build mast and boom out of laminated spruce.
3. Finish rudder components

Posted: Fri Jun 10, 2005 8:50 pm
by richwink
Hi

Another update. Completed fairing the outside of the boat and cut the daggerboard hole.
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Finished sanding the hull and took a picture of the bow of my boat.
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It cracked during assembly and used to look like this so not a bad repair. Centerline will always be a little crooked at the bow... okay for a first build.
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Have the mast rounded and the outside fiberglassed. Will post those soon.

Posted: Wed Jun 22, 2005 12:20 am
by richwink
Hi

Been busy with two weddings one in alberta (my brother's) and buddy from high school in ontario. Got some time on the boat however. Anyway here is the update:

Also had to order another gallon of epoxy.

Cut 24" of the mast in half and clamped and glued mast. Not sure how it will work as it is still drying.
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I couldn't put the bent section toward the stern as the mast is actually 3x3.5" with a slot for the bolt rope of the main in the 3.5" section.
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Glued centerboard trunk in and cut the fibreglass out of the slot on the other side.
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Woke in the morning the day I was going to sand and paint and realized that I hadn't installed the skeg. :oops: Did this with fillets and some fibreglass cloth cut to fit. Used an interesting clamping arrangement to keep everything straight. I think I got this from the help files?

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Didn't take a picture of the hull as it stands right now but I have effectively faired half the hull using a belt sander and sanding off two layers of epoxy. Would have liked to quickfair but couldn't get it from the marine supply store I go to. I only get a 1 every 3 months crack at it as it is 250 miles away (edmonton). Bought all my rigging and tarp for sails.

Posted: Tue Jul 05, 2005 2:02 pm
by richwink
Time for another update.

Starting sanding the hull. It started like this:

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Used a belt sander and I now need to recoat the boat with epoxy because I only have about 1.5 coats on it now. The majority of the bumps are gone. I think I effectively faired the whole boat using standrad epoxy instead of something easier and cheaper (quickfair). Learing learning learning...

Tried straightening the mast but it didn't work. The focus is to get the boat to the water rather then get everything perfect. I only split the mast for 4 feet down the length and should have cut 8 feet. This is it today.
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Mast step made. 7 pieces of 1/2" ply glued together. The bottom piece doesn't have a hole as it will butt up to the bottom of the boat. Still have to drill the drain hole and plane it to the shape of the hull.

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Got the two pieces of the spray deck glued together using butt blocks. Will post more on this later.

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Glued 2" stroyfoam into the boat under the seats. I used two tubes of silicon to attach the foam to the roughed epoxy coating. Hopefully this will hold. If I had planned better I should have cut the foam first and placed in right after rolling the second coat of epoxy. Used some expandable foam to seal around the edges. Not sure how effective this will be but makes me feel like I tried to make things good.

As an aside I calculated an area of about 20 ft2 covered with stryofoam. With 2" thickness that means I should have 200 lbs of boyant forace. I might buy some more and double this to 400 lbs.

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Next steps:
1-install next layer of 2" stryofoam.
2-cut holes in frames A and B
3-plane mast step for hull shape
4-glue in mast step and a block for the main sheet tackle.
5-paint interior of frames A and B.
6-glue benchs and spray deck down.
7-paint outer hull
8-fair cockpit

Thats all for now.

Posted: Sun Jul 17, 2005 11:53 am
by richwink
Hi All,

Been going like crazy to get this thing ready for vacation...

Anyway the update:

Got the stryofoam under the seats in and put expandable foam around them.

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Cut holes in frames A and B. Also drilled 1" holes between all the frames under the seats for drainage and air breathing.

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Another view of the underside of the spray deck as promised. Notice the but blocks to join the two halves together. Don't do this as it will stiffen the deck up and make it really hard to bend into place when gluing down. It will however, make the deck really stiff to walk on... like everything else in boat building a compromise: this time between pre-stressed components and strength of deck once assembled.

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Got the mast step completed and glued in. Used a hand plane (you have to get one of these for trimming as it is so much fasted the sanding!) to shape the bottom of the step. It is 7 layers of 1/2" ply with the top 6 layers having holes cut out for the mast to slide into. Gap is about 1/4" all the way around between mast OD and hole ID.
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One last look before gluing spray deck and benches.

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Seats glued down. I had a gap all the way around the seat which I covered with a layer of 6oz cloth.
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Installed spray deck but had to use screws to hold down becuase of the butt blocks used to hold the halves of the spray deck together.

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Mast partner glued down. Used screws also.
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Rigging fittings: Had to remember what each one was for...
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First time the mast was stepped it leaned to the port side (also the side that the mast bend is on) This was because the hole in the mast partner was about a 1/2" off to the port. I opened up the hole and used a wedge to push the mast over in the hole to get the mast vertical at the base. Will have to use the stays to hold the mast vertical...

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Painted the hull white (one coat so far) and installed all the rigging fittings on the mast and boom. Have to install rudder fittings and the bow port hole cover.

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It is really looking great. I am tempted to leave the spray deck and mast partner clear but I used a slow hardener which isn't reccommended for clear coat. Will probably end up with a blue deck, white cockpit and wood rails.

Posted: Sun Jul 17, 2005 12:17 pm
by jasonmcintosh
Your boat's looking great. As you say, "learn, learn, learn..."

How are you making the mast? I don't quite understand. You got a single, long, round piece of hardwod?

Jason

Posted: Mon Jul 18, 2005 1:39 pm
by richwink
Hi Jason

Using a solid piece of wood is not deisrable as the knots of the one piece effect the whole cross section. With laminated spruce you should only get areas of weakness on half of the mast at any one time.

The plans call for a 20' x 3" diameter wood mast. Being in Alberta where spruce is plenty I went to the local lumber yard and picked up 5 2x6x8s planning to cut one in half. 8+8+4=20. However I cut 12" (8 to 1) scarf joints and glued everything together. Only after everything was done did I realize that 8+8+4-2=18. So back to the store and get 6 2x6x8s. Re-cut the scrafs and glue. When it was all said and done one of the boards pulled and I have a 2" bend at the top of the mast. I am planning to put it up in my garage with a paint can on it to slowly bend it back. The book "building the new instant boats" by dynamite payson(sp?) has the procedure in it.

1. Get lumber. If you have time dry the lumber for a month before cutting, this will allow time for the wood to dry out and any warpage should be avoided after building the mast. I didn't do this...

2. Cut 2x6x8s to 1.5x3.5x8' on a table saw. You need to use 2x6 instead of 2x4 becuase the corners of 2x4s are rounded.

3. Rout out the hole for the bolt rope on the main sail to run up. I used a 3/8 half circle bit and routed each of the 6 boards. Use a circular saw later to cut the slot for the sail to run out once the mast was glued together. You can see the final cross section below.

4. Cut matching scarf joints by using a power planer (i rented one) and laying the boards side by side. Be sure to check that the slots for the bolt holes are lining up. Also stagger the scarf joints from one side of the mast to the other by at least 2'. I used a hand plane to smooth out the power planed faces and then roughened them for glue penetration with 60 grit an orbital.

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5. Set up a gluing stand using saw horses and a level. Use string to get the mast as straight as possible. Leave the string up to allow for adjustment once the mast is assembled and the glue isn't dry yet.

6. Glue the mast and clamp. Adjust until straight. Be sure not to get glue squeeze into the slot.
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7. Wait for glue to dry.

8. Cut an taper you desire with circular saw. I tapered three sides... the ones without the slot.

9. Mark the corners of an otagon using the jig shown below. The outside pencils touch the sides of the mast and the inside pencils draw the corners. They use the fact that a 45 degree right angle triangle has sides that are 7 versus a hypotenous of 10. One thing with my mast is that because it is oval I should have made two jigs once for the 3.5" sides (the triangles are not 45 degree right angle triangles) and one for the 3" sides of the mast. I used only one jig and spaced the pencils 1.4"-2"-1.4" (7-10-7). This is good enough for what we are doing.

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10. Run a circular saw down the glue joint on the side of the mast with the hole to allow the sail to pass up and down the mast.

11. Cut the excess material with a circular saw with the blade set at ~30 degrees. This should remove the bulk of the material that needs to be removed. I used a hand plane to plane out the corners and get to lines on all four sides. Then used the hand plane to turn an octagon to a 16-side-agon :lol:

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12. Belt sanded the mast to round by eye with 120 belt.

13. I oiled the mast with unboiled linseed oil and screwed the fittings in. Will end re-doing the mast every couple years. Also I dipped the screws into epoxy prior to installation of the screw. This seals the hole. I removed the screw waited for the epoxy to dry and reinstalled the screws.

14. The one thing I have left to do is to open up the slot to 3/4" wide above the gooseneck to allow insertion of the bolt rope when raising the sail.

I also made my boom using the above method from a side piece of wood. Used a cut off remaining from my rub rails that was 1.5 square. Marked the octagon and hand planed to 16-sides. Used belt sander to take from 16 sides to round.

Hand planing spruce is easy, and the above probably took about 12 hours including cutting the scarfs twice. I had the mast shaped in two days. About an hour of sanding for both boom and mast. DO NOT try this without a power planer... it takes forever.

The book I mentioned above also shows how to make a hollow mast by using the same method but installing 1x2s in between the 2x6s. This will give you a 3.5 diameter mast with a 1x.75 hole down the middle for the halyard. I couldn't find really staight 1x2s and the added labor of more scarfs etc wasn't worth it. If I break this mast maybe I will try it when I have more time. Also the mast with a hole wasn't really that good for putting a bolt rope hole up it. For a rig similiar to the dory 12 this would work great. What is that rig called again?
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Anyway thats enough for now.

Posted: Mon Jul 18, 2005 7:58 pm
by jasonmcintosh
Thanks for the detailed description.

That's quite an operation. I'm amazed that you're _only_ off by 3".

I don't understand the reason for the slot(?) in the mast. What's going to be going up and down in there? I had a sailboat once, and it just had eyes on the mast for the main and jib. Nothing went up and down except for the sails...

Jason

Posted: Tue Jul 19, 2005 12:55 pm
by richwink
Hi

I am using a bolt rope in my sail, which is a piece of rope that the sail material is wrapped around on the luff of the sail. The bolt rope runs up and down the slot in the mast instead of using a track. Use of a track or a slot is required for a stayed mast. For an unstayed mast I could have used rings or a sock over the mast, stays prevent those from moving up and down. See this online book for rigging:

http://www.glen-l.com/free-book/rigging ... l#contents

Also a picture from the book:

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Hope this answers the question Jason.