Head Stay chain plate

[Joegunz]

I've got a CD 33 - (#12) called Miss Maggie that is kept at Rye Harbor New Hampshire in the summer. The bronze head stay plate is lifted off the steam area slightly. When looking inside the chain locker at the bolts for the head stay chain plate, and bronze deck plate, all looks good. The nuts are tight and haven't moved either up or down. Has anyone observed this and/or fixed it?

[Jim Walsh]

I've got a CD 33 - (#12) called Miss Maggie that is kept at Rye Harbor New Hampshire in the summer. The bronze head stay plate is lifted off the steam area slightly. When looking inside the chain locker at the bolts for the head stay chain plate, and bronze deck plate, all looks good. The nuts are tight and haven't moved either up or down. Has anyone observed this and/or fixed it?

"Slightly" is subjective. Objective information would be very useful in this situation. A photograph would be ideal or a couple precise measurements. It is very good news that you see no evidence of fastenings which appear to have been compromised.

[Joegunz]

Thanks for the reply. You're correct "slightly" is not a very good description. I'll take measurements and a couple of photos first chance I get. Thanks again.

[Joegunz]

Here are a few pictures. The gap between the bow plate and the fiberglass at the stem is about 1/8 inch. The nuts and bolts that hold the head stay and bow plate are all tight and don't appear to have moved in anyway. I think this gap has been there awhile, not sure how long. It was noticeable last year.

[tjr818]

Hmmm. I don't see anything tying that replacement backing plate down to the hull. Original backing plates had either a vertical web or a welded piece of rebar tying the backing plate to the hull.

[Joegunz]

Interesting----not shown in this pic is an aluminum plate that those bolts go through. I'll take another picture and look at how that is tied into the hull. Thanks for your response.

[hilbert]

I don't see anything tying that replacement backing plate down to the hull.

Doesn't the stainless chainplate on the outside secures it to the hull?
It would be helpful to have a picture of the deck to better understand what forces act on the head stay plate.

Just spitballing here, but since it is a boat that suffers hard freezes maybe the expansion forces from freezing water separated the plate from the deck.
Freezing water can expand by 9% with a force between 25,000 and 114,000 psi.

[John Stone]

The 33 does not have a bowsprit. Don’t know if that’s true for all of them. Looks like the headstay and furler, if that’s what you use, are fully dependent on the SS chainplate. So the top plate that appears to have separation between it and the deck “may” be independent of the headstay. It might simply support the anchor roller and thus the backing plate is part of the anchor roller. Nonetheless, you don’t want a gap like that—saltwater will/has gotten in there. Nothing good can come from it. Crevice corrosion, galvanic corrosion, freeze-thaw, etc.

If in fact the deck plate supports only the anchor roller, then a backing plate without the vertical parts normally seen on CDs with bowsprits, is not necessary.

I also notice what looks like a fastener, at end top of the chainplate secured into the deck plate. That would appear to tie them together so what one suffers may befall the other. So, it needed to be addressed. Might not be difficult if you can get in there to remove the nuts.

Remove the nuts and that top fastener. Remove the deck plate. Examine it. Perhaps you need a slight increase in the deck height under the plate to align the top fastener hole that secures to the deck plate (if I am seeing it right—more pictures will help). If so, that’s not a difficult project. West epoxy and 404 with some 406 fillers under the plate. You packing tape as a release agent under the bronze plate (is it bronze right?). You might consider replacing the backing plate with a piece of 1/2” thick G10so there is absolutely no flex in the backing plate.

After fairing, I’d bed that plate with butyl rubber or 3M 4000uv with butyl donuts around the bolt under the deck plate. Make sure the bolt holes are all chamfered. Use teffgel where the SS fasteners run through the bronze. Tighten the nuts and not the fastener heads.

Interesting project but not difficult in the scheme of things. Do address it though. Try to understand why it separated and that will often guide the solution. Keep in mind my comments above are based on a couple of pictures that don’t show much. More pictures will help.

[Joegunz]

Thanks John Stone and Hilbert. I'll take more pic's. This conversation is helpful in sorting this out.
The deck plate is bronze and the stainless steel chain plate carries the roller furler / head stay load. (No bow sprite.) The SS chain plate is fastened into fiberglass of the stem with 4 - SS fasteners and one additional one into the front of the bronze deck plate. (5 total ) I agree you don't want any gap under the plate! There is also and aluminum plate (?) under the deck to backup the fasteners for the bronze plate.

[Joegunz]

OK here's a couple of more Pic's. The bronze deck plate is basically the mount for the anchor roller, but it has one screw in the front from the head stay. That seems like the only upward force on the plate. The head stay however has four additional screws into the stem that don't appear to have move up at all? So it's a bit baffling why there is a fairly uniform horizontal 1/8 inch gap between the fiberglass of the stem and the bronze plate? The pic from the underside is fuzzy, but there doesn't appear to be a gap between the aluminum backer plate and the glass of the deck. I'm, thinking of building up the stem and or caulking it to eliminate the gap and calling it good. Any opinions?

[John Stone]

If the plate is cast bronze it may be the bottom is not flat if the foundry did not sand out the “draft.” Draft are angles built into the pattern that allow the pattern to be removed from the sand without distorting the cavity. If that is the case it could explain why there is an even gap all the way around the deck plate. In other words, the plate is not flat on the bottom.

I’m not inclined to fill gaps with caulk. It’s just not the way I do things. Doesn’t mean it will not work though. If it were me, I’d take the plate off and investigate why there is a gap. I’d check to see if the fiberglass is flat, is the plate flat, etc. Then I would make a plan to create a perfect fit.

If something is not flat, then, probably, I’d mark the deck where the plate fits and sand it well with 80 grit. I’d tape everything off. Then cover the underside of the deck plate with packing tape. Trowel some epoxy thickened with 406 and 404 onto the deck and push the deck plate back into place. I’d use a stir stick to scrape off the sqeeze out. I’d make sure the hole on the deck plate lines up perfect with the hole in the chain plate. I’d let the epoxy cure then pop off the deck plate. Remove the packing tape. Put the plate back in plate and redrill the holes through the deck. Led the hardware and reinstall the bolts. Then you would be done. No painting or gel coat repair required.

Then again, it might be something else and you won’t know till you remove the deck plate and determine the cause.

[hilbert]

I agree with John that a proper fix involves removing the plate, dealing with unexpected complications, preparing the surfaces and rebedding.
Trying to injecting something from the edge into a narrow gap is at best cosmetic and may create a problem by trapping moisture/water between the plate and deck.

As you are new to this board, I don't know how long you have had your boat. Do you know for a certainty that the gap is new?

Although I tend to be obsessive about such things, I would consider this to be a very low priority.
As E.B. White said, "If a man must be obsessed by something, I suppose a boat is as good as anything, perhaps a bit better than most. A small sailing craft is not only beautiful, it is seductive and full of strange promise and the hint of trouble."

[Frenchy]

My anchor roller base is also a bit separated, though it's not as bad. The after part of it looks down against the deck but forward,
I think that chain plate bolt is holding it a bit high. - Jean

[hilbert]

I doubt that there was much attention paid to achieving a flush joint during construction of the boat.
Having the chain plate bolt fixing the position of the bronze plate high is a complication.
I had to build up the deck at the bow to create a flush joint with the bowsprit on my 28.
There was about a 3/8" separation between the bowsprit and the end of the deck that was filled with crumbling sealant.
After removing the bowsprit, I also found that part of the forward most deck was filled in with something like marine-tex putty.

[Joegunz]

Thanks everyone for the info! I think the "Gap" has been there quite awhile. It was present when I bought the boat in 2014, at least at some level. I can't say if it's any worst now? It's good to hear another CD33 has a similar bow plate gap. ("Miss Maggie" was called "Metro" and was in New Bedford, Ma. at that time.) Seems like a simple job, maybe 3 hours to re-bed the plate? (So, 3 hours X boat work factor of 4 = 12 hours + a trip to the marine store) The boat is in good maybe excellent shape with most everything so might as well fix it correctly!