Flush thru-hulls flange/head size

[BourbonS]

Dear Forum,

Apologies in advance for this "long read".

Could you please kindly help me with this:

I've got my Catalina 42 1992 last November. Besides ...well... "everything else" I am replacing now all thru-hulls and valves.

Previously/originally these were all Forespar Marelon thru-hulls and valves except two bronze on holding tanks macerators outlets.

Without any intent to start another "Marelon vs. Bronze holy war" I'd would like to mention that:
1. All Marelon thru-hulls were in pretty good shape when I removed them.
2. A broken handle on one of the Marelon valves in a process of very careful "exercising" of it and a leak as an unpleasant "side-effect".
3. One valve completely broke in half on a very minor force applied while I was removing a hose. (Good for me that this happened while she was on the hard. Otherwise .... <your imagination goes here>...).
4. One Marelon of "93 series" looked good ... but had periodical minor leak on open/close.
5. Bronze valve (I removed one) looks very good. After some exercising/lubing works smoothly. From the inside looks good as well. I don't see any disturbing signs. Bronze thru-hull also looks not bad.

So basically Forespar / Marelon valves currently is not an option (or an option that I will consider as absolutely the last one). Except that one "93 series" valve which has two barbs and I need exactly the same. Part number is 931233 which is not available online and should be ordered directly.)

So without Forespar I have these two options left (all 3/4 except one 1-1/2) :
1. TruDesign valves/thru-hulls. For example TruDesign Ball Valve with load bearing collar
2. Groco bronze flanged with the backing plates;

Ordered both to try.

During "dry-fitting" I realized that I feel uncomfortable with TruDesign because that "load bearing collar" completely blocks any access to a thru-hull without complete removal of the valve. Not sure why I don't like this. Probably because of a hypothetical case of a leak between a thru-hull and a hull that I will not be able to temporary fix. Thru-hull's flange diameter is 1-2/3'' but Forespar 3/4 thru-hull fits OK. For now I don't consider TruDesign as an option for now.

With Croco valves I am having another problem: Catalina has the "flush thru-hulls". Only Forespar has thru-hulls with a flange/head of that size (please see the images).

Outer flange/head diameters for comparison:
- Forespar is 2.430(61.72mm)
- Groco is 2".

I feel not very comfortable with a smaller one but was unable to find a bronze flush or mushroom 3/4" thru-hull with the similar flange size as Forespar.

Technically Forespar thru-hull looks and feels like has the same NPS thread as Croco flanged valve NPS thread. Given that Groco flanged valve will be on a backing plate a smaller flange head should be OK.... r-r-r-ight ?

So my question is what should I do:
- Use a bronze thru-hull with a smaller flange?
- Use Marelon thru-hulls with a Groco bronze flanged valves?
- Other options ... ?

Any ideas/hints/thoughts/considerations are needed and appreciated.
Thank you.

P.S. Some other related thoughts. I ordered one backing plate from Groco and I didn't like it at all. This is an overpriced cut made of PVC panel that look similar to what I see in Home Depot. I honestly not sure how it will bond to an adhesive but have some doubts about any "epoxy-based" one.
Got these instead.

The images to compare how both tru-hulls fit.

[GordMay]

Greetings and welcome aboard the CF, BourbonS.

[BourbonS]

Thank you!

Found this from Buck Algonquin with flange diameter 2-1/2".

Ordered to try. Will see.

[Rumrace]

Congrats on the sweet boat. I don’t think Hunter ever used a poor product deliberately. I replaced on ballcock on a Jeanneau cause these threads made me paranoid. I’d want to replace the flange with the factory spec in either material. I don’t think there is any question the bronze is the best material and the base they put in is sure secure.

[BourbonS]

One more question.

That "93 series" two-barbs seacock likely can be done differently using a regular flanged seacock and some "tee connector". But again, can't find any tee with NPT thread (except this one)

not sure whether this would be a right way to go or just get a new "93 series" and don't bother?