Molds for 26D Dagger Board and Laz Hatch.

[finding41]

Finding,

If I attempted to make a new rudder myself, would wood be ok? What kind? and does it have to be glassed? Or could it just get 20 coats of something. Half tempted to add the couple inches on the front as many have done and similar to the ones available.

Of course I would have to guess at the foil shape and use table and circular saws to rough shape it and sand it to shape. If nothing else I would have a spare.

I have a wood one on the one boat and the original on the other.
I prefer the wood as it is kind of a 0018 foil shape. (Kind of.... When I got it it was a 2x12 with rounded edges....) I used my 4" belt sander and some 36 grit paper and sanded it untill I got the foil shape. It took a while! It's OAK!
The wood rudder is toast now because water got in between the glass layer I put on and now there is more rot. I had fixed a couple spots before but now it is too far gone. So soft I could push my knife through the rudder!
I can`t have that for the charter. So I`m going to make a couple this week.
2x12 pine. I`ll rip the board 3 times to get 4 long pieces and glue it back together flipping every other board over and upside down. (If it gets wet ever it won`t warp so much. )
I will be using epoxy to glue it just because I have a couple gallons kicking around and wood glue isn't good in water!
Here is how I plan to remove the material to get the foil shape:
I will take the board and draw the foil on both ends.
Then using my planer I will take the material off a bit at a time. (But how..?)
I will take a thin piece of wood the same thickness to get the piece to the level I want to remove and attach it along the length so the edge that I want to remove the material from is higher and on the same plane as most of the drawing on the end. (I use short brad nails to hold this piece on You could glue it and wait an hour before plaining.)
Once one side is done remove the wood and put it on the other side and do the same process. You may have to adjust the thin piece of wood to get the same exact angle.
That is how I make the 15* angle when I make those big thick old window sills. Usually 6x10". I have a mill mill me the 6x10".

If you don't have a plainer...
Table saw. Have the blade as high as it will go, stand the wood on the long edge and set the blade to cut the angle you drew. (NOTE: you want a 1/2" flat piece on the back end of the foil for strength and it will help sturdy the wood while cutting.)
Cut the angle. Flip the board around and make the cut to the other side. ( It Should still be one piece of wood with a V cut along one side.)
Set your fence to cut the pieces off while the board is flat on it's side. make both cuts. (Now 3 pieces of wood.)
Set the blade to trim off the angle of the front of the rudder. Trim off each side of the leading edge.
(Now you have 5 pieces of wood.) I would start sanding the big one from there. Don't bother trying to remove more material with the table saw. (It can and will kick back!)

I plan to do this this week and will take pictures of how I do it.

I'll take a picture of my wood rudder tomorrow and post the rot and the shape.

 

[Doc_holiday]

When you say you are going to rip it. Do you mean ending up with 4: 3/8 x 11-1/2 pieces or so you have 4: 1-1/2 x 2-5/8 pieces? In otherwords will the cut be with a band saw or with a table saw?

I was thinking 2 3/4" x 12 with the grains opposite?

 

[caguy]

You da man, Finding. Enjoyed following your thread. It's a nice feeling knowing that you can replicate hard to find parts. Visited your charter site and now I understand why you need backups. Have you ever considered going with the Mac 26S? Their swing keels are made for short waters that tear apart the daggers of forgetful sailors.
On the dagger you made are you making two half molds and mating and filling? Unless I missed something it wasn't clear to me.
Keep posting and thanks,
Frank

 

[finding41]

I'm going to rip it length ways so I will have 4 long pieces of wood. Flip ever other piece to change the grain of the wood. (So any warping will cancel its self out with the next piece of wood.)
I didn't get the wood today. I plan on getting it tomorrow.
Today was the last clean up day at the yacht club. I fixed the stairs going down to the beach from the race hut. They get washed out by the flooding in the spring.
I also picked up another dinghy and took it to the storage place ware Topiary is. Then shopping for 2 matching coolers and some white PVC pipe for the anchor holders.
her are some pictures of my wood rudder. It has always been stored out of the water! I cut the loose bits of fibreglass off.
Note the leading edge. (Wrong shape! I left it that way when I smoothed the rest of it out. The back looked the same.)
Also notice the flat trailing edge. From what I've read this is ok for the 0012 and 0018 foil design.
Oh the knife... It didn't go through like butter. More like cheese.
The last pic has some rough measurements. Note: the bottom measurement goes right across.

 

[finding41]

The new dinghy:
Watertender 10'
For some reason I thought it was made of fibreglass. It's not. It's plastic.
It's good for 120km/h on the highway.
I need to get ores for it now.

 

[Doc_holiday]

I Picked up an 8' 2x12 and cut it into two 4' pieces. I made an emergency rudder just to keep on board. The other one, I did as you said and ripped it. I glued and screwed the pieces after cutting them to shape. I need to go get a cheap belt sander as it will take forever with an orbital palm sander.

When it's all done, I'll glass it up. This one is just a copy of the OEM shape

 

[vizwhiz]

I made an Excel spreadsheet that will give you the profile of a symmetrical NACA airfoil like that (0012, 0018, etc.) if you'd like it. It will give you the dimensions based on location from the leading edge, or something like that...been a while. I was planning to make a back-up rudder also, but haven't gotten there yet. PM or email me your email address if you are interested and i'll send it to you. (Caveat: it's in inches, not metric, but you could probably change that in the spreadsheet if you know how to use Excel.)

One way to check the shape of the foil if you don't have a table saw or a planer (i have neither) is to draw the two halves of the foil shape on the edges of blocks of wood, cut them out so the hole is the shape of the rudder profile, and hold them together with a big rubber band so they can be spread apart easily but without falling apart. (Even one half would do in a pinch.) You can slip it up and down the length of the rudder as a template and see where the wood is still too high, doesn't fit right, etc.

 

[Doc_holiday]

I did make the foil close to what the original is. I plan on using the original for a while till this one is complete and glassed. I HATE sanding so I'll do it as I get the ambition.

 

[finding41]

I got the wood and ripped it today. A 10' 2x12. I also laminated it with epoxy. I popped by a buddy's work site and used his table saw. (Mine have stuff piled on them.) I also broke the door knob on my shop door... (Actually the guts that pull the latch back. I twisted too hard and bent it inside... The "solid core" door has expanded and sagged with winter and the recent rain and got tight and was weighing heavy on the latch. That's why it got stuck and I kept twisting... Until I could turn it all I wanted and nothing would happen.) So I put a new latch part on the door. (Note: Remember to get a new door. Not a wood one with glued sawdust inside!)
I got at the laz hatch cover and added 2 layers of glass on the edges. I think a couple more thin layers on the edges and one over the plywood and I'm done. I think It's better a bit more solid.
I also got to the fibreglass and gel-coat touch ups on the boat.
I ground down each old hole and ground out some of the bigger gel-coat cracks.
I've seen different ways of attacking these cracks. Anything from using a pointed end of a can opener or scraper to gouge out the crack to a grinder. I have 5 grinders... So I used the small one. (4")
After grinding I swept the boat off and then wiped it with ass-atone. I used chopped strand mat to patch the holes.. I'll grind off the high spots later and give a coat of gel-coat.
There are tricks to getting the gel-coat the right height. I'll go over that when I get to it.
It's been a very busy day. I also got the bikes and trailer out of the garage. (I hang then in the rafters...) Helped clean the yard. Got grocery's, made supper, (jerk chicken and beans and rice.) Also took the hardware off the tiller handle so I can refinish it next time I have some resin out.
Here are some pictures.

 

[finding41]

Hey guess what happened when I when to put everything away for the night............
My rudders fell apart!
The epoxy didn't kick between the pieces of wood! It did ware it squished out and ware I dripped it on to the wood.... Also kicked fine on the laz hatch cover I did with the same pot of resin.
I think the moisture in the wood played a part. It was select kiln dried pine I purchased for this project. $24.40 after tax for the one 2x12 board! (After my discount too!)
It's not dry.... Maybe I miss read it... It may have said that they drove by the kiln (kiln drive) with it one the way to the lumber store....
So I put the table and set up in my 1 car garage... Lots of room with all the stuff I have in there... NOT.
The clamps take up a bit of room. They stick out kind of far.
Oh well at least things will be dry in there for the next few days.
I re-did the lamination with a new pot of resin. I'm not going to touch it until tomorrow when I most certainly will impale myself on a clamp while trying to get the garbage can out. I'll fight the urge to remove the camps and leave it to dry another day. I will put my fan on it to keep the air in the garage moving.
More pictures... Me after grinding the gel-coat, bike and trailer, De-laminated wood, Glued again and the light I got at Princess auto. (both mine are done.)

 

[finding41]

I've kind of left the rudders be today.
I got thinking last night about how I have them set up and clamped.
I have them sitting directly a piece of 6 mil plastic. That because I don't want it to stick to my table. I think I should allow for a air space under the boards. (I don't think this is required but thought why not.) So I placed 2 pieces of wood under the rudders between them and the plastic.
I'll leave it clamped for another day or so before I remove them.
We are looking at 2 strait days of rain here with highs around 10c and lows near 0c at night. I'll leave the fan on.

 

[finding41]

I got the last coat of glass on the hatch cover today! I'll pop it out tomorrow or the next day. I put another coat of glass on the motor well trim mold too. (One more and I think I'm good to go for it.)
I took the wood for the rudders out of the clamps. It didn't fall apart! So I drew the shape on using measurements form the old modified rudder.
Wow that old rudder was rotten! It broke apart when I unbolted it. (I'll cut through it to see how much rot is there after I get the new ones made.)
I got a little Gung-Ho and forgot I had to shape the rudder in the plainer before I cut out the forward shape that fits into the aluminium rudder holder. (Crown thing...?) So I drilled pilot holes and will screw it back together tomorrow after my drill charges. (I was too lazy to go to the car and get the electric drill, or use the screwdriver.)
If it's not raining tomorrow. (Or snowing.) I will try to get them plained down. I will do this in the back yard because I don't want the dust in the garage. I can just rake it up out back and scatter it in the flower bed. I'll turn some into the compost bin too.
I also did some research for building my arch tower.
Priced aluminium tubing and 100' of 1" OD, plus 3' of 1 1/16 ID will be about $130 plus tax. (Not bad.) I will probably braise it together (Or mig weld it if I can find a small roll of flux core aluminium wire for my welder. Or If I can find a good deal on a bottle of gas for the regular aluminium wire.) and bend it myself with jigs screwed to the bench. (If someone trys this at home... Screw the bench to the wall first. Or the bench will move.)

 

[Picflight]

I have seen several videos on how to fiberglass and I have noticed that they use large quantities of resin. I am a beginner and have only worked with 1/2 oz with 4 drops of catalyst that gives me 15-25 minutes of work time depending on the temperature.

How are you mixing larger quantities and how much work time are you getting out of it? I am assuming that is catalyzed resin in your picture.

 

[Bob McL]

To get the final shape the fastest....

. . . the best tools I found when I did my rudder was an electric hand plane (mine is DeWalt - Harbor Freight has one too) and a grinding/shaping disc on a 4-1/2-in grinder. The disc can be found at WoodCrafter (Sorry for the lack of focus).

I know everyone says that plywood is a bad choice, but I used baltic birch (same as good cabinet makers use) since every layer is the same thickness. I glued 1/2-in pieces using epoxy to get the total thickness I wanted. The layers of the plywood show contour lines like a topographic map so you can judge the shape.

Then I covered with four layers of epoxy/glass except the leading edge had an additional layer put down first

 

[finding41]

I have seen several videos on how to fiberglass and I have noticed that they use large quantities of resin. I am a beginner and have only worked with 1/2 oz with 4 drops of catalyst that gives me 15-25 minutes of work time depending on the temperature.

How are you mixing larger quantities and how much work time are you getting out of it? I am assuming that is catalysed resin in your picture.

Yes that is catalysed. But it is black tooling gel-coat with a little bit of liquid wax. The wax helps it cure properly and could help it release...?
I mix about what I think need for each thing. (This pot is 2/3 full. 500 ml It only covered 2/3 of the DB. It goes on a little thicker than I expected. About twice as thick as I expected. I brushed it though.)
The mix is about 1.5 -2%. (I just guess! I have a 2 0z container of hardener that is supposed to do 1 gal of resin. So I go by feel.... I guess.)
I try not to use too much and make sure I mix it for 2 min. (Yes. 2 min. If I've got too little hardener than at least it will cure evenly. Even if it takes a bit longer.)
After I let the gel-coat harden I start with the chopped strand mat then woven cloth. (I've seen guys on YouTube say wait until the gel-coat is tacky then start with the glass.
I've had problems with air bubbles and the gel-coat lifting off the piece. So I let it get hard then go at it with the glass.
Expect to get about the same amount or a little less working time as you are getting now. But remember that a bigger pot of resin heats more quickly. All of a sudden! Try and get it on the piece so it doesn't harden up while in the pot. See Picture: I had that in the pot for over an hour... Still too runny for my gelcoat on the motore bracket trim. So I went in the house and had 2 chocolate Easter eggs and came back out. (5min.) Hard as a rock! And Hot too.
Have all your glass cut. Plus extra! I use 3 pairs of rubber gloves. 1 pair the fits snug... Then two pairs of light plastic bag type that are easily removed. I only use one pair of those at a time but keep the others handy if I need them. (About 1/3 of the time.)
I use lots of disposable 1" paint brushes. I also put 6 mil plastic under what I am working on. Just incase.

 

[finding41]

Well I'm kind of disappointed with the way the hatch cover came out. It lifted and wrinkled in odd areas... I bet it happened becauseI was a little gung ho with the layewrs of cloth. I didn`t wait over night for the gel-coat to dry.... I waited a few hours and thought it was set enough. I wounder if those areas were ware I poked around more with the brush trying to get the glass to sit down properly.... I would have expected that in the corners and along the curved edges... There fine.
I don`t think there is much I can do with this other than put another coat of gel-coat on and flatten it out.
Or I may be able to kind of save it.... I could grind out the bad spots and give them a coat of gel-coat and put it back in the mold.... Hey it's worth a try.
If it looks bad I'll just put a coat of gel-coat on by brush and add some anti slip sand.
I`ll post photos later.

 

[finding41]

Here is the carnage:
The 3rd pic and the 4th pic go together. Ie; that is the spot in the mold (4) that made the spot (3)
Any ideas?
Was I right about the messing around with the glass that lifted it?
It's all set with no soft spots so I figure it was mixed properly... I paid special attention to this batch of gel-coat. I really stirred more than the 2 min of other pots of resin.

 

[finding41]

So Friday after work I went to Heritage Marine here in London and and found out what went wrong with my gel-coat.
I didn't have it thick enough and didn't let it set up long enough... I only let it sit for 4-6 hours then went at it with the glass and more resin. I should have waited 24 hr.
The (Something or other that I can't remember.) in the resin soaked through and lifted the gel-coat. The guy I spoke to called it alligatoring.
So now I'm going to grind down the high spots and clean and re-wax the mold and get the piece un-waxed and ready for another whack a the mold.
I will coat the whole mold and the low spots on the piece with gel-coat and clamp them together and hope for the best. (No air pockets.) May just coat both the whole mold and the whole piece to be sure...
If that doesn't work... I'll paint gel-coat right over the whole top and add an anti-slip sand. I hope it doesn't come to that.
I didn't get anything done to the piece yesterday or today. Too busy with a friends wedding.
I did get into the garage for a few min tonight and cut off my dowels on the tiller handle and sand them flush. Tomorrow if it's not raining..... I'm building a 2 story play house in the back yard. If it rains I'll get to the gel-coat on the cover.
I picked up the aluminium tubing that I am using to build a arch yesterday. I'm going to braise it together. I've never braised aluminium wiht aluminium rod before so it should be interesting. YouTube make it look easier than traditional braising rod. Looking forward to this.
Someone let them selves in to my car last night and stole a set of my keys so I couldn't get into the shop today. I left the door unlocked by mistake and... Pain in the butt! One of the guys that worked for me is dropping off a key tomorrow. (I let him use the tools he doesn't have.)
I'm not concerned with loosing a set of keys as none of them work at the address they were taken form.

 

[finding41]

No time for the hatch or DB this weekend. Too much sawdust in the air...
A wedding yesterday and moved a playhouse today. The an open house at a new marine store and repair place just out side of town. (Free hot dogs!) I just went to introduce myself but I did have 2 hot dogs.
Today I worked on the rudders for about 3 hours. I ran them through the planer and then hit them with the belt sander. I took off a triangular chunk from the leading edge of each with my skill saw first.
I drew lines on the back edge ware I wanted to stop sanding at and sanded that edge first working toward the middle of the rudder. Then I sanded the leading edge to the centre line I had drawn and kind of worked my way back. Working from the leading edge you can feel how the shape is coming out. So I sanded the high spots to get a nice flow going back and along the length. I used 36 grit on the belt sander and 100 grit on a sanding sponge to even things out a bit more. I still have work to do on the one in the picture. It started to rain so there was a mad dash to get cleaned up outside.... (Go figure... Rain!)
The other rudder suffered lamination failure again! This time while I was sanding it. So now it is glued with a polyurethane glue and is clamped. I'll leave it for a few days again... I think it may have something to do with the rain and wet lumber. The poly glue loves moisture so that wont be a problem any more.
I was planning to just give each rudder a thin coat of tight weave cloth but now I've changed my mind. I'm going to cover each with heavy glass and Kevlar. I have about 40'x 3' of the stuff sitting in the shop.
I think I will try and rig some type of vacuum bag process for them. I'll see what YouTube and I can come up with.

 

[finding41]

I sanded again tonight and I broke another epoxied joint...
I can't believe this. It's only this one rudder... Cut from the same 2x10...
I noticed it was separating while sanding and glued and clamped it again. It is almost finished. The other one is done to my liking. See pictures.
I've been thinking about how to make a vacuum bag jig and think I have a viable idea.
I'm going to use a contractor garbage bag and a aquarium pump as my vacuum pump. I'll put the pump in the bag and run the tub out of the bag.
If it doesn't work I'll go with one of my shopvacs. It as to run all the time during curing so I've been shying away form using them. I have an old metal one that I may sacrifice for the job. I think the new plastic ones would just melt the motor housings after a while. (I've done that to a plastic housed electric drill before...Mixing tile mortar.)
I'm going to close the bag with butyl tape.
I'm giving second thoughts to the length I've chosen for the new rudders. I may shave them down a bit so they don't reach quite so deep. There really isn't any need for them to go so deep.
After I get the tiller handle and the rudder sanded I'll get back at the laz hatch cover and the DB mold.