Winter Rudder Project

[tmw]

Anyone have hints for how to put down fiberglass?  I put the "middle" of the fiberglass on the trailing edge, that way it has a double layer on the leading edge where there is overlap.  Getting the corners to work flat isn't very simple.  Without a professional vacuum system, is there a best practice or hints to make it sound?  I've done one side thus far, and man that stuff is smelly--admiral will probably not be happy when she returns...

[GeeW]

I know it's a bit late for this layer of glass, heavily radius the edges and put 'darts' in the cloth as you need, to get the cloth round the edges. (Darts as in clothing and not pointy things!). I also put the overlap on the leading edge.
Having said that it loks like you've done a good job.

[tmw]

Hmmm, darts look like they would have been helpful.  They seem like a great idea.
Anyone have guidance on bubbles?  Are they like death in fiberglass, or just things to avoid and fill in later?  Maybe I should have watched a couple youtube videos on it first.

[Cats Paw]

Possibly a different fiberglass product and polyester resin would have made rounding the corners a bit more easier.
Check out the video on Fiberglass selection.

https://www.youtube.com/watch?v=ioj1YBm6bJY

[tmw]

My lesson learned is that if I started over again, I would not have used the fiberglass mat as one big sheet, but cut it up into smaller sheets sized for where they would go.  My edges, especially corners, are total messes, and not sure exactly how I will clean them up eventually.  I suppose it's a good thing I have until spring to be ready.  The Tap Plastic videos are pretty helpful.

[tmw]

With the snow and colder temps, and working in the shed because the epoxy smells really bad, this project has been going slowly.  During the plateau, I had an idea on which I'd love to hear your thoughts.  This idea comes from centerboards and a different set of boats (obviously).

The idea is to add about five pounds of lead cast into the bottom of the rudder so help ensure it doesn't float.  I think that would be about a cup (volume wise) from my rough calculations.  I think I can buy this for about $17 from the Amazon.com, and then melt it and cast it onto the bottom of the rudder, and then encapsulate it with fiberglass and epoxy.

What do you think?  I've been avoiding foam to minimize the floating, and would adding lead ballast possibly help as well?  Glad it's not summer, so I have plenty of time to work in this.

TimW

[Duckie]

I bet if you tossed it in the bath tub, it would sink like a rock.  You have a downhaul on it right?   I wouldn't worry about getting it down to where it belongs if you have a downhaul.  I have a tendency to rely on my downhaul to make sure that my rudder is in the right place because just hanging it from the pivot bolt won't get it far enough forward to knock down the weather helm.   If you are concerned about cleating off a downhaul, I use a pop up cleat on mine.  If the rudder grounds out, the cleat releases.  Otherwise it holds the rudder in the down position even when hard pressed by the water. 

I am rebuilding one rudder this winter and have built a new one for two of my boats.  It is kind of fun isn't it?

Al

[tmw]

It's warming up, and I'm back to finishing up this project, because it has to be done before I can sail.

Question about laying fiberglass:  What do I do with my imperfections where there is space between the epoxied glass and the wood?  Do I sand out the glass and try again?  I had a horrible shape on the bottom, as my glass laying technique over the corner sucked, so I sanded it out and tried again, which was better, but not great.  There are other places (e.g. look at the trailing edge on the picture above) where there are gaps between the epoxied glass on the layer underneath.  I'm finding that putting more epoxy on top doesn't seem to help.  Any guidance from people who know fiberglass much better than I?

Thanks,
tmw

[crazycarl]

this is a project that has been on my list for years.

let me start by saying that i'm no expert in boat building, but i was a pattern/model maker for over 20 years and the fiberglass casts i produced had to be stable and strong.

this is how i would go about it...start by placing a long thin piece on the trailing edge, then a piece on either side, with the side pieces overlapping the trailing edge piece.  next a long piece on the leading edge, overlapping the side pieces.

you're better off using smaller pieces that overlap than trying to cover the whole project with one piece.

with that said, it is also better to apply several layers of a lighter weight cloth than one heavy layer.

next, after sanding down any large humps use a good fairing compound to fill any voids and smooth out the surface.


now, for your situation, sand down the high spots and fill the low ones with epoxy.  then use the fairing compound to create a smooth surface for painting.


again, i've never done this project, so maybe someone who has can speak up.

c.c.

[JTMeissner]

tmw, having gone through this, a couple of options...

In this photo you can see where the fiberglass resin ate away the foam underneath (my bad for not testing prior).


In the large areas, I cut through the fiberglass and used thickened epoxy to fill in the holes.  You can see some of the hardened epoxy after being sanded down in this photo.


In smaller areas, an option is to drill a hole of about 1/4" and use a plastic plunger or plastic bag with the corner cut to squeeze in a thickened epoxy paste which will fill the void (like cake frosting).  Consistency is a trick you gain over time, and currently I'm getting much better at adding the right amount of thickener (current choice is wood flour) to get the consistency I want. 

For the smallest of "bubbles," it may not be worth doing anything.  The fiberglass has sealed over the gap and is now a solid layer (which is why no amount of resin on top will penetrate).  You have to get under, or you can just leave it.  With another layer or two of glass and resin, the likelihood of it being an issue is minimal.  It's going to be hidden under paint anyway.

For my rudder, I used a single large sheet on each side with an overlap of about 1/2" at the nose.  Fiberglass does not like to stick around sharp corners, and the heavier the glass, the more rounded the corner needs to be.  Using the technique described by Carl is a good one for the trailing edge.  Another choice is to lay down a layer of thickened epoxy before you lay the glass or tape.  This will help prevent the small gaps/bubbles as you apply resin over the top.

In the end, it may not be perfect, and you can see the low spots on this rudder indicated by the remaining paint.  With the thickness of the bottom paint I'm going to apply over the primer, I'm not sure how much will gained by trying to get it perfect before going out sailing again.


-Justin

[Duckie]

I'm right in the middle of glassing the new rudder for my sailing canoe.  I did very much like you and folded the dry glass over the leading edge of the rudder and clipped it behind the trailing edge with clothes pins.  My intention was to hang the whole affair by the clothes pins so that the leading edge would be forced to lay down tight.  That didn't happen.  Instead, I clamped it in my bench vise, and painted on the goo.  I ended up with a couple areas where the glass didn't adhere to the wood on the leading edge.  After it cooked off I carved off the fabric that wasn't adhered, and now today I intend to fill the voids with thickened epoxy.  I am going to try using baby powder to thicken the stuff for the first time.  I will make the goo thick enough that it will stand up and fully fill the void so that I can file it down fair.  If you put enough epoxy in the hole it won't matter if there is no glass in it.  The glass is mostly there to stabilize the surface like tape would do on paper.  As long as the epoxy is thick enough, it alone will water proof the area. 

If you have areas where the fabric floated up, you can sand that down fair as long as it isn't a huge spot and don't worry about going through the fabric.  As long as it isn't a big area, the same applies.  As long as the goo is thick enough, it will water proof the spot.  I would not advise this on a large area like a hull bottom, but on  small piece like a rudder, I don't think it is a big deal.  If these defects drive you nuts, sand the whole thing fair and put another layer of glass on.  If nothing else it will be good practice. 

Al

[tmw]

So, for an update, I had the rudder finished glassing and ready to go.  It was painted white, and seemed to work.  Here is an installed picture:


The rudder worked very well, easily controlled, and did occasionally rotate up, but for the most part stayed in the normal position (reaching over was pretty easy to push back down).  I want need a method to hold it down, like others have built, as the next upgrade.

However, evidently my glassing wasn't waterproof near the trailing edge.  The result was that one side warped off the metal blade.


Now I'll have to think about what kind of short-term and long-term fixes  I can get in place, since it's no longer winter....

[Chris D]

I am sorry to see that tmw, you put a lot of work into it. I wonder if some through bolts would work, and then some glass over that. When I did my rudder, I draped the big pieces of glass over the front edge of the rudder and brought them together at the backend. After it dried, I sanded it, and then I flipped the rudder over so the aft side of the rudder was up and I ran a few lengths of glass strips on that edge and let it dry. I then sanded the edges down to try to fair it to smooth. It seems to be holding up pretty well. Hope this helps.

Chris

[tmw]

Thanks, I'm thinking I could always wet it down and use clamps to force it back into shape.  I sanded too much on the trailing edge, trying to get to a nice point (or relatively close).  It's a good learning project--I had a suspicion the wood wasn't the best material, but was willing to try and learn as I went.  It doesn't float as bad as a foam rudder probably would, but that is my current next best alternative (and probably much more work than clamping it back into shape).

[Chris D]

Yeah,  the foam in my rudder definitely wants to float! I think Bob23 made a wooden one, maybe he has some pointers.