What type of thru-hulls are these?

[ElCapt Drew]

Hello all,

I've just started a refit on a Paceship Northwind 29; an old, but sturdy girl!

My experience with fiberglass boats and of boats this size is very limited so I appreciate any advice at all..

I'm replacing all my thru-hulls with bronze units. All the thru-hulls onboard, except 3, are of the standard design (a thread pipe with a backing nut). However, I'm not sure what to do with this type:




These are located in my head, but there is also another one under the galley.

How do I go about removing and replacing these? Do I have to cut them out somehow, or is there suppose to be a backing nut on them under the fiberglass?

I would like to replace them with a more serviceable design.

[ozskipper]

No idea about the top one. The bottom one looks like standard 90% gal plumbing pipe corner attached to a glass inlay-ed flange..

The top one appears to have flange glassed into the hull.

As they are totally glassed in, you will probably have to use a hole saw to remove them entirely. Then patch the area and install new ones.

[leftbrainstuff]

Both look like junk. Is the top bronze and the bottom pic galv? Hard to tell from the pics.

I suggest the flotation test. Cut them out. If they float reuse them. Else replace them with bronze Grocos.

There are some good blog posts which explain the proper installation process.

I like your obsession to replace them.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[CSY Man]

.
I suggest the flotation test. Cut them out. If they float reuse them. Else replace them with bronze Grocos.

Funny guy.
What they did with witches 500 years ago. If she floats, she is guilty, burn her at the stake, if she sinks, not guilty..

[ozskipper]

Originally Posted by leftbrainstuff

Snip

I suggest the flotation test. Cut them out. If they float reuse them.
Snip

I shoulda tried that with the ex-wife!

[ElCapt Drew]

Originally Posted by leftbrainstuff

I suggest the flotation test. Cut them out. If they float reuse them. Else replace them with bronze Grocos.

Haha

I figured the response would be something like that. Looks like I'm in for some fiberglass work!

Many thanks

[Lodesman]

The top one looks like a Blake or copy of. Are you certain it's not bronze?

[geoffr]

Top one is definitely a blake - we just removed them from our boat as we have changed to Marleon.
Also it has not been installed correctly - It should have a backing plate and be thru-bolted (if it's like ours). You will need to cut the glass away from it to remove it from the boat.

Good luck!

[deblen]

If you can get a 4" disk grinder with thin cutting blade in there,you MAY be able to cut them off flush to inside of hull. MAY be able to drive/cut the thru hull portion out without cutting a large hole re-building.
Just a thot

[Roy M]

As suggested earlier, remove them however you can. Chipping around the base with a heavy hammer and chisel may aid considerably, followed by a pipe wrench and the heavy hammer to spin it out. Grind the inboard side of the hull reasonably flat. Epoxy a four inch square piece of 3/4 inch plywood over the hole(s). Then fill the exterior side of the hole with epoxy and filler to make it fair with the hull. Then drill the hole for your throughhull fitting, epoxy seal the plywood backing pad and hole. Then install the new fitting with what ever sealant you prefer (I'm not going there) and you are good to go.

[Shrew]

They both look Bronze to me. Aside from the gel/epoxy slopped all over it (beige) and the plumbers tape on the threads (white) the rest clearly looks like a green patina. Galvanized metals don't typically turn green.

[Cheechako]

Originally Posted by deblen

If you can get a 4" disk grinder with thin cutting blade in there,you MAY be able to cut them off flush to inside of hull. MAY be able to drive/cut the thru hull portion out without cutting a large hole re-building.
Just a thot

Yes, no reason you have to cut a hole in the hull. Just remove the glass layup holding the flange on the inside.

[ElCapt Drew]

Appreciate the ideas!

I think what I'll do is try to grind around the flanges and see if there is anything to work with. Other than that, if that proves to be no good I'll probably try cut the head off the outboard side and push the unit into the boat.

I'll let you know how I made out.

Btw, i'm fairly sure the large fitting is bronze and the smaller fitting is bronze with a galvanized elbow on it.

[deblen]

May help. Replacing Thru-Hulls and Seacocks Photo Gallery by Compass Marine How To at pbase.com

Other subjects http://www.marinehowto.com/

[Lodesman]

If it is a Blake, then you can tell from the image that the flange halves are held together by four screws. The nuts are probably covered by fiberglass/bondo/whatever - so you may want to forego the angle grinder and go easy at it with a chisel. If you can unbolt the nuts, it might come apart easily enough. Why is it that you don't want to keep using the Blake? They're pretty bomb-proof, and easy to maintain.