Uh Oh... Deformed Stemhead Holes

[hriehl1]

1968 Hinterhoeller HR 28

My surveyor passed my standing rigging and (visible portion) chainplates. I pulled two chainplates to inspect for hidden issues and all was OK. But an item he missed and I just noticed is the stemhead. Both stemhead holes, for the forestay and the headsail tack, are deformed with elongated openings and metal-ridges (visible in photo). The prior owner said they tuned rigging to bring the mast as far forward as they could to reduce weather helm... they may have been a bit aggressive in their adjustments. So...

1. Is there anything short of a new stemhead to get me into a safe situation... like some sort of collar-plate with new holes?

2. If a new stemhead is called for, any suggestions on hardware sources and installation methods? Or is this something just best left to a pro (which I am not)?

3. Given a) the weather helm condition, b) the possible need for a new stemhead, and c) my desire for a bruce/claw anchor roller fitting on the bow... would a short pulpit with anchor roller and a more-forward forestay attachment address all needs? If so, any thoughts on capable sources in Mass-NH-Maine to perform such a mod?

4. Last, just to be thorough, I understand old blown out sails can also contribute to weather helm... and my mainsail has certainly seen way better days (and headsails aren't that much better). Would new sails be the better way to address the weather helm situation?

As always... Thanks. Hank

[Hirilondë]

Elongated holes for attaching rigging or the tack of a sail are only issues if the remaining metal around the hole is insufficient to maintain structural integrity. It is not the same situation as an elongated fastener hole which is no longer a secure way to fasten. You don't know the surveyor missed anything, only that he did not say it was an issue. If in doubt, call him/her. You payed for a survey, it should include the right to ask questions.

Blown out sails are by far the most common source of weather helm. Sails are a foil, and blown out sails are a terrible foil. Moving your forestay forward will change your sail plan. Unless you know something about your boat that the designer did not then you are probably making a mistake.

[hriehl1]

Thanks; unfortunately, the survey occurred 15 months ago and I'm quite sure he has long-since forgotten.

As to the remaining metal still being adequate, do you have any guidance on how I could make the determination whether what remains is adequate or not? I believe the stemhead is aluminum... if I were to remove it would a metal shop be able to shore it up with welded material and then re-drill?

As to changing the sail plan, your advice is good advice.

Thanks... Hank

[LazyGuy]

Hank,

Check this out. Near the bottom of the page. Rigrite is a good outfit. Chuck is an upstanding guy, give him a call. It might be more reasonable than you think.

http://www.rigrite.com/spars/kenyon_spa ... Flyer.html

The elongation of the holes MAY be a problem because now, rather than the forestay pin distributing the stress evenly around a symmetrical hole, you have a point load. The math is similar to a woman wearing high heels. A 100 pound woman standing barefoot on the floor assuming 25 square inches of foot surface is applying 4 pounds per square inch on the floor. If she has heels on with a 1/2" square heel (1/4 square inch), with her weight on one foot she is applying as much as 400 pounds per square inch. Same issue. One pin touching a small surface of an elongated hole will pull at the remaining metal much harder than a round hole with a proper sized pin.


Give Chuck Poindexter a call

The other option is to have the stem head holes welded and redrilled. You can see if the yard where you are located has a recommendation.