Helm Seat Cracking on 2008 26M

[beene]

...don,t know how many times it,s almost decapitated me when my heads been down there !

Cantcha jus move the location of yer cockpit bar?! Jus sayin'...

Oh boy John, he knows you.

Ray

Nail on the head!!!

ROTFL

Just made my day!

And ya, J, use a freekin rope to hold the dam seat up when going for another pint!

G

[Highlander]

Hi guy,s that,s how I come up with a lot of my mod,s ideal,s Knock knock how come I never thought of that before bang bang darn helm seat again

Listen when u drop a penny on the cockpit floor & it rolling aft towards the Davy Jones locker their,s no time to b screwing around securing a helm seat

I do not have to leave the cockpit to get another Pint I have cold storage access lockers built into my cockpit

As for that little cable on the Helm seat I thought that was when u lifted the seat u hooked it onto the back belt loop of ur pants so as not to fall overboard while Peein

Just goe,s to show u r never too old to learn !!

J

[45Plus+]

I also have a crack to deal with on the starboard side of the helm seat. You can see fiberglass and the cracked gel coat so it looks like I have some cleaning up to do to set repair fiberglass sheets in there so I can finish things up flush and smooth on the top visible side. I can repair the bottom side to but since its out of sight, I am not too concerned about it being super pretty. I am more concerned with how to get a color and finish on the top side that matches (or sorta matches) the rest of the helm seat so I don't need to worry about refinishing the whole thing. Thoughts?

[OverEasy]

Hi 45Plus+!

We have a Mac26X with the same problem! (It was existing when we were adopted by Over Easy).
Seems like a theme with the swing up helm seats… they swing DOWN HARD! (32 feet per second squared!)

Good luck on getting any gelcoat to match a sun and weather aged original surface though.
That’s gonna be tough.
I’ve planned on addressing ours several times but other ‘stuff’ gets in the way.

Phase 1:
The benefit of delay is that we’re now hoping to start progressively painting at the beginning of next season starting with all the removable hatches as well as the helm seat. These have all experienced some wear and tear since they were manufactured back in 2001. ( I have too )

For the helm seat lip that takes all the shock load when it inevitably slams down I’m going to also modify things so the area where the base of the seat contacts the cockpit side bench area is now the first point of contact with a compliant bumper like a nitrile or viton foam rubber pad. That will somewhat distribute the forces over a larger more robust area. Ideally when all is said and done the helm seat backrest lip will not be in contact anymore so the problem won’t reoccur.

I mention this as I’ve tried several small touch ups of the gelcoat and have not had much success in getting it to match the existing aged factory surfaces. The boat repair and body shop guys I’ve managed to have talked to have all pointed me in the direction of new paint rather than new gelcoat. While gelcoat ‘May’ last longer the prep and blending refurbished surfaces to existing surfaces is much more intensive and the overall process much more expensive. Paint is more forgiving, easier to prep, apply, blend and touch up as well as much less expensive by a considerable amount over gelcoat. A three layer two part epoxy paint job will easily last a decade, and probable much more, at a fraction of the cost of gelcoat.

If you’re desiring to match the existing gelcoat color paint is also easier to tint.
If you can get a flake big enough to get a paint store to run in their spectral analysis thingy machine they can tint the paint for you.
For a touch up you can probably just use a good Rustoleum one part exterior epoxy paint.
They tend to self level reasonably well and bond well to clean oil free surfaces.

Best Regards,
Over Easy

[Ixneigh]

I rebuilt mine to be in two pieces so all I do is move the seat part to connect or disconnect the engine linkage. I don’t have to hinge up the back part. Even though I made it extra strong, it also has a very small crack, from when it slammed down once.

Ix

[45Plus+]

This is certainly one of a handful of areas where Roger let cost get the better of durability as far as design and manufacturing criteria go. Interestingly, when I sit on the helm seat, all my weight seems to be taken by where the seat portion hits its bearing surface - not the back of the seat where I have the problem. No telling what caused it but it is there staring at me each time I go to sit down. Of course the Admiral notices it too and wonders each time if the boat is going to sink....

I noted that the PO (s) have done touch ups with just paint and while its noticeable when you look at, its not too noticeable to a casual observer so I think I am good with fiberglass reinforcement and paint. I could take the whole seat off and run it over to a paint shop for a colour match but I will only do this if my repair job is more distracting than the current situation. I guess I would have to give the seat a good clean and polish to get it to a state that represents the target colour and finish - though maybe leaving it a bit dingy would be more representative of actual operating conditions

Adding some thin foam strips to dampen the impact is a good idea though I guess you have to be careful not to add too much so as to not put too much unintended pressure on the seat hinges.

A project for this fall.... (along with dealing with a similar sort of gelcoat crack/bubble in a troublesome location along the upper rub rail).


Thanks for the input guys!

[tuxonpup]

I was annoyed that the line to my rudders had it’s tail caught under the seat back when I first got my 26X, now I think the original owner knew exactly what he was doing.

[OverEasy]

Hi All!

Just an Engineering perspective on what may have led to this issue….
Looking at the helm seat and the cracking of the seat back opposite the hinge I can see that it is a kind of part-to-part tolerance issue between the seat and the cockpit. The parts are a “it just fits” where the attempt was made to have the seat bottom contact would match with the seat back contact at nearly the same moment. Kind of a tough thing to do with precision machined parts never mind with molded fiberglass and gel coated layup parts! Some times the seat back is gonna contact first and sometimes the seat bottom is due to the real world aspects of manufacturing. Add in the aspect that the seat bottom is a post molding machine cut surface Contact face and the seat back is an as molded surface it’s most likely that the seat back is gonna have the greater dimensional variability and generally contact first.

(In Design Engineering we generally cover this as Product Interface Geometric Dimension & Tolerancing…. Where unless there is an over riding concern one would avoid trying to have two contact regions from mating at the same time..just make the one actually carrying the most functional loads of the ‘Rumpus Maximus’ the point of contact which would be the seat bottom-to-cockpit bench….)

So inevitably there are gonna be cases where the back rest contact is gonna contact before the seat bottom first… this seems to generally occur on the side opposite the hinge for the examples I’ve seen for the Mac26X and suspect this is also the case for the Mac26M. It can also happen on the hinge side as well where the seat back contacts before the seat bottom but without the impact loading aspect. When, under static conditions (I.e. not slamming closed), the seat back contacts first all the loads imposed bumpy someone sitting in the helm seat are imposed at the thinner seat back first before the seat structure deflects to allow contact with the seat bottom. This imposes a strain that it isn’t as capable of handling. Eventually adversely strained areas tend to fatigue. Now add in a couple dynamic momentum slamming shuts to the equation and it only exacerbates the problem. The thinner seat back is gonna take the brunt of the abuse.

So I figure that when I get around to fixing the helm seat on our Mac26X I can fix a couple aspects at the same time.
A) The first is to repair the damaged fiberglass of the seat back.
B) The second is build up and reinforce the contact lip of the seat bottom so it will always contact first on both sides but particularly on the side opposite the seat hinge.
C) The third is to add some compliant cushioning material to the seat bottom contact surfaces to moderate and distribute the potential momentum impact kinetic forces that will inevitably occur if/when the seat falls shut. UV resistant Nitrile or VITON foam padding should help with this.
D) The fourth would be to make sure at reassembly that the hinge is adjusted such that the seat bottom is what contacts and Carrie’s the vertical loads and not the seat back.

I don’t doubt that somewhere along the line this probably was the original design intent but just as probably that intent was either not continually communicated or was circumvented during the production and/or assembly processing. It’s not an uncommon thing to occur, especially when there are low tech processing and multiple personnel turn overs as was most likely the case when the boats were in volume production at the MacGregor facility. Expecially when the consequences only showed up as the boats were being used by owners in diverse locations.

Now it’s time to get back to being productive and see if I can convince the Admiral to go out on the boat for a couple hours…..

Best Regards,
Over Easy