I need to make a quick repair to a rudder that is delaminating at the top seam. I have some new rudders on order, but I've procrastinated too long and have a regatta this weekend.

The crack is about 6-7" along the top seam of the rudder. It is the Tiger white carbon reinforced rudder. It appears as though the separation is due to twist of the rudder in the casting. I can put a screwdriver it the crack and separate it slightly.

What is my best repair without totally grinding it down and reglassing?

Here are the 2 options I've been thinking about:
Option one: gap the crack open with a screwdriver and inject West System epoxy resin with a syringe so it can seep into the crack well

Option two: Use a Dermal tool to cut away some of the loose gelcoat and create a slight V. Then fill it with 3M 5200 silicon adhesive.

So what is the stronger repair? West System epoxy resin or 3M 5200? I have both the resin and 5200, so it would be nice to not buy something else. Or is there something better that's worth buying?

Option 1 for sure. 5200 is better as sealant. It's decent as glue but I'd go with West.

Clean it out well,

Open it with the screw driver and then epoxy it

Close it down tight, clamp it and keep it warm.

I sailed for about 9 months with a rudder fixed like this no problem

How old is your epoxy? I am currently having a problem with an epoxy mix not curing properly.

I'd test a small sample and make sure all is well.

Ahhh;

Good point; make sure it is almost in date.

West System is really good about shelf life. I've had some two year old stuff that works just fine although the hardener was terribly discolored. With epoxy, however, you need to be sure that it is good room temperature before mixing though - I've had some incomplete cures because it was cold when I mixed.

As for the repair, I would stay away from 5200 because it will remain flexible and allow the crack to propagate. I would open the crack slightly, mix up some slow cure West System, heat the mixture to reduce the viscosity and warm the rudder up (heat gun but sunshine might work), pour into the crack, remove screw drive, repeatedly squeeze the crack to work in the epoxy, and clamp. I bet it would hold fine.

If you really want to get fancy, and depending on the shape/nature of the crack, I would seal up the crack and apply vacuum to suck in the epoxy.

My epoxy is pretty old, but I need to get some new hardener. I don't think there is a date on it,but I would say it's probably 6-8 years old.

Is this delamination crack common among the Hobie Tiger Rudders? I also noticed several stress cracks in the gelcoat where the rudder meets the bottom part of the casting. Our other rudder is also showing some stress cracks there.

For one weekend, spreading the crack and getting epoxy down in may hold. However, I've had rudders split down the seam on two occasions. Both were Hobie rudders split down the front seam in the area of the lower casting. One was an old-style EPO, and the other was a Hobie 20 rudder. In both cases, I got epoxy inside the split as well as wrap glass around the split (which can be difficult since you may not be able to make the rudder wider). In both cases, the rudder still eventually re-split.

Personally, I would try to get some glass or carbon on the split to help hold it together. There is a lot of load on those rudders. Try to make it stronger than original afterall, the reason it split was because it wasn't built strong enough.

Regarding old epoxy, I've been told that the epoxy/hardener doesn't like to be stored below freezing (32F) because crystalization can occur and thus effect curing. However, if you're epoxy does end up crystalizing, all you need to do is put it in hot water for a while (can't remember if it had to be boiling).

sm

Yes, you are correct. If it crystallizes (you should be able to see the particulate), you can put the container in some hot water and stir to re-homogenize it.

I know a couple of people that have had it happen on older rudders (2002). The biggest pain is that you can't get the "old style" white rudders anymore. You either upgrade to carbon or upgrade to the new rudder system that requires new gudgeons.

I pumped some of it out and it appears to be fine.

I did also have this problem with one of my H20s, but it was 6 years old before it cracked. This Tiger is only 2 years old only been sailed 6-8 times each year.

We've ordered the new style Tiger rudders, so hopefully they'll hold up better.

If it is that old, do a test before using it.

Crystals in the resin will fall to the bottom, and suddenly you are left with a lot less resin than hardener when you need it the most.. If you heat resin to get rid of the crystals, make sure you check that there is not a layer of chrystals left at the bottom.

Most trouble with epoxy are actually caused by not stirring long enough before applying. Mixing it cold is not a problem if you heat it enough to start the reaction once applied. But it have to be stirred well, which is even harder if it's cold.

In my case, poor stirring is the most likely culprit. After days, it finally did harden. It was like a "gummy bear" at first.

If you would like, I will sell you my older Tiger rudders. They are in okay shape. I will sell the set for $250 plus shipping. I have the newer ones so I do not need the older ones anymore.

I already have an ad in Catsailor that mentions the rudders so I feel fine mentioning them here.

Later,
Dan

Dan, thanks for the offer... check your PM to follow up.

From older postings on Hobie rudders: reepoxy the crack, then add a 1 inch x 5 inch piece of Kevlar tape. It will never split again.
If you do this when new, it will never ever split.

Use Marinetex; you can buy it at West Marine; hardens as steel and you can sand it as a piece of wood. Good stuff

I just used West 2 pot epoxy 105 / 205

I've used Marinetex and really like it for small puncture and crack repairs, but it do think it bonds as strong and will separate under stress. Also for this repair, I think using something more liquidy to seep into the crack may work best. We're potting it this morning. We'll see how it holds this weekend.

Thanks for everyones help.