ID Rudder Material

I have damage to one of the rudders on my 1974 H16 and need to identify the type of material. It looks and feels like ABS but the center seems to be a little foamy, more like a manufacturing artifact than a formed-in layer. It also has the letters "AH" formed into it. Does this sound like ABS?

An original '74 rudder is definitely ABS.

Otherwise known as Always Breaks Suddenly

Describe damage, did you drive with a rudder down, chip it, or did it break off clean at the waterline. If a upper corner broke off, throw it away if it is plastic of any kind. Save your time for sailing and your money for a permanent cure. If you were seeing foam in a plastic blade, my guess is that the upper corner broke out.

Possible solutions; buy a new nylon blade, buy a new fiberglass blade, make a new wood and fiberglass blade, buy a set of EPO2s. The EPO is the best option for performance, but the nylon blades can hit rocks with little effect. Are you careful or more likely to let the blade kick up on the sandy/rocky shore. If you are not careful, sail recreationally, pick the nylon blade. (i think its now nylon)

You said in an earlier post that you have spent too much on this hobby. My guess is that you are hooked and it is time to spend too much once again.

Foamy inside? Tiny bubbles and hard or soft? I suspect these may be lexan if hard. The inner core sometimes looked like the inside of a bone.

If if sheared off below the rudder casting... likely ABS, but the insides were not usually / ever bubbly.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Cause: Not certain but probably when I got blown into shore (boat on its side). As I was leaving shore I noticed the problem. In between time I did what I could to protect them but the wind was gusty.

Damage: Corner is missing from the bolt hole up. The rest of the top was cracked about an inch in from the top edge and nearly to the outer edge. I pulled it the rest of the way off.

Foam: Bone is a perfect description. It feels like the same material as the rest of it with the foam fading into solid.

Repair: I completely understand "throw it away" and I intend to buy another, but now it's a challenge. Being retired I have some time on my hands. I've read enough about repairing ABS to think that it can be done with a bit of bridgework and filler.

Build: Does anyone have plans for making fiberglass rudders? I was thinking of foam core similar to lightweight aircraft. Thoughts?

Here is what one person here did

http://www.jaimezx.com/Boating/Hobie/part3.html

Has anyone tried to make a mold or the rudders?

Two piece mold (two halves) to make two skins out of fiberglass or carbon with epoxy resin, joined in the edge with a strip of fiberglass or carbon tape and then fill with high density (16pound per square foot) expanding foam.

anyone?