- This topic has 19 replies, 9 voices, and was last updated 8 years, 7 months ago by
.
-
Posts
-
-
I’ve got to replace at least one through-hull before launch and I wanted to hear from anyone who’s done the job before I go at it.
The one that needs replacing had a loose handle, and when I attempted to tighten the nut it very easily sheared off. These are the smaller sized ones, not the 2+ inchers used for cockpit scuppers and the like.
It is similar to the one pictured – I believe installation involved first attaching the sea-cock+integral base to a backing block with screws, then screwing in a through-hull from the outside.
I’m thinking that I’ll have to undo the screws, then cut the “mushroom” head off the outside with a ginder, then see if I can pull the whole thing (through-hull+sea cock) into the boat. Has that worked for anyone who’s had to take this on?
Pearson 424 cutter - "Effie"
Attachments:
Marine_Hardware_Bronze_Sea_Cock.jpg
-
Yes you’ve got the right idea about removing the exposed mushroom. Here’s how I did them.Use a grinder with a thin cutting blade and cut 3 or 4 slices through the thru hull mushroom. These cuts should be across the diameter of the mushroom, with the grinder blade perpendicular to hull. (Be sure to were solid eye or face protection, gloves, protect your neck, etc and wear a hard hat during this as breaking blades is very possible). When you have a star pattern cut, the mushroom will be a collection of wedges. The take a cold chisel and pound thru wedges out by hammering the outside edge of a wedge toward the pointy end of wedge. They break off easily after you get the first one out. If you boat is like mine the fasteners and base plate will be rotten and once the mushroom exterior is removed you can use a hammer and a piece of hardwood to knock the seacock and thru hull into the boat. On a few I had to cut nuts but most drifted out easily. On my board I cut scarfs and fiberglassed the holes. This because even when I was replacing the seacocks, I generally moved them to a more accessible location. Using this technique, you can remove several thru hull/sea cock assemblies in an hour–fiber glassing is another story.tkx,rb
-
-
-
Every one of mine, large and small bronze perko, simply came out with a slight turn with a nipple wrench (fits inside thru-hull and grabs the two tangs there) and a monkey wrench on the inside. One of them unscrewed by simply turning the nipple wrench. One of the large ones only had 2 3/4 full threads holding it. The whole episode was very frightening for me because of how easy they came out. You can cut or grind a piece of metal to fit inside a thru-hull as a nipple wrench then have someone inside with a monkey wrench or jam it somewhere as I did and do it alone.
Ken
Taking what comes as I get it, using it all as much as I can and trying hard to leave all the shit behind.
Attachments:
2014-01-10.jpg
-
-
My experience has been different so far. First I stuck a file in (read that this worked elsewhere) and used a wrench from the outside – shattered the file.
Then I tracked down a grooved tool (concrete chisel possibly) that fit right in with the “tangs” inside, filling the role of a nipple wrench. Locked a pipe wrench on it and turned, shearing off both interior tangs. Now I have a smooth hole, so I think it’s cutting time.
Deciding now whether to Sawzall the head off the mushroom or go with the above grinder+pizza slices idea.
Pearson 424 cutter - "Effie"
Attachments:
PSX_20160614_152947.jpg
-
-
-
On my previous vessel I had a similar experience. I used a 4” grinder with a cut off wheel, as I recall. Just sort of sliced it off with several cuts, right at the hole. Alternatively, I suppose you could go with a thicker wheel and just grind into the hole until the wheel contacts the fiberglass, then move on and do it again and again, in sort of chain drill fashion. Either way, you can’t really mess this up too badly. If you cut into the hull too badly just fill with thickened epoxy.
David
#189, Blue Moon
-
FYI for the forum – Perko 3/4″ seacocks that appear to be identical to what I removed are $99 for Port Supply members… or $250 on West Marine. Find a Port Supply member to buddy up to if you need to do this job.
————————————
So once I finally decided to cut (“pizza slice” method with the grinder) this was actually SUPER easy. Maybe an hour, but 30 minutes next time. I think I’m going to remove and replace the few I’m having trouble with, then either refurbish or scrap the ones that I’m having difficulty closing.
Super simple – for those potentially searching this via google, materials –
-grinder+cutting wheel
-a cold chisel or two (thanks Discoverie) – I bought these after I cut the slices and saw what size I needed, and the wrenches necessary to take the hose off the seacock and the nuts off the backing plate
– long rod that fits in the through-hull
– heavy hammer (one of those mini sledges worked great for me)
1. Disconnect seacock on the inside from the backing plate. Mine (3/4″ Perko) was attached
2. Cut “pizza slices” in the “mushroom” part of the through-hull. You can go all the way through but I didn’t on 4/5 cuts – just means a bit more pounding later.
3. Whack the slices towards the center with aforementioned mini sledge + cold chisel. They will bend to the center and perhaps get stuck on neighbors, but you can either cut again or keep whacking – enough will knock it loose
4. After all slices have fallen off, stick the metal rod in the hole (my through hull had a 90 degree bent pipe attached, which helped) and hit with the hammer. One tap freed mine.
The 4th step was my fear – that after I demolished the through-hull I would discover that the whole thing was attached with 5200 and would still be impossible to remove. Based on how easily it came out (one mediocre strike), I think that was completely unfounded fear.
Summary – this was SO much easier than anticipated. Thanks for the advice everyone, and hopefully this post helps someone in the future.
Pearson 424 cutter - "Effie"
Attachments:
2016-06-14-13.43.41.jpg
2016-06-14-15.12.06.jpg
2016-06-14-17.35.30.jpg
2016-06-14-17.45.17.jpg
2016-06-14-17.46.55.jpg
2016-06-14-18.03.22.jpg
-
-
-
-
-
-
Prior to owning my 424 I owned a Pearson Alberg 35.The sea cocks were bolted on with no mushroom through hulls, just the solid glass core exposed. The bolts were countersunk into the hull and the nuts were on the inside.The bolts would rot a way and the sea cocks stayed on by wishful thinking and luck.Bronze or plastic mushroom through hulls screwed into matching sea cocks is the way to go.Bolting would put the heads of the bolts to close to the mushroom head.I enjoy reading everyone comments on the up keep of the fleet.RonS/V Patricia Bess#217
-
I’m very happy that it’s not bolted through the hull. More metal through the hull seems unsafe to me. The flange bolts seem to do their job (anhoring the seacock to keep stress off the through-hull) just fine through a backing plate. That Alberg design sounds scary.
I’m all for the dremel method, but nobody has actually shared which attachment they used. I did look at Lowe’s and Home Depot and saw nothing to fit the bill. Sizing also seems like it wouldn’t be easy.
Pearson 424 cutter - "Effie"
-
-
This past winter I replaced 6 seacocks. Bought a step wrench which worked well with a large crescent wrench. All the thru hulls unscrewed with force. Scary part is some only had 3 threads into seacocks as Pearson cut thru hull too short and could have engaged more of the seacocks!Decided not to add backing plates because hull is at least 1/2 inch thick and old seacocks worked well for 35 years. I enlarged hot water tank access in aft cabin to get better access to port cockpit drain seacock. Old seacock was frozen and unreachable!!
Now I will turn it monthly.
-
- You must be logged in to reply to this topic.