Removing Thru Hulls for resealing

[TLCObsession]

I need to reseal one or more of the thru hulls on my Adventure 208. One of them has a slight gap to the hull and I am getting some water coming in. In this case it is the fish locker on the starboard side. I can get the hose off, but can't budge the backing nut. I can attack it one of 2 ways:
Get a 1.5" socket and try and get the nut off
or
Get a (expensive) thru hull step wrench, have my helper hold the nut on the inside with an adjustable wrench and try and turn the thru hull out. The chrome on teh bronze is a bit pitted, but I am not sure it is worth replacing it. I just want to rebed it with wither 4200 or Boat Life. If the problem one comes out reasonably easily, I will do the others.

Advice?
Are the step wrenches available for plumbers any different than the expensive Buck Algonquin ones?

 

[SkunkBoat]

https://www.greatgrady.com/threads/deck-drain-scupper-surprise.28979/post-182609

The Husky spanner worked well for the tightening/loosening and the homemade 2"PVC pipe wrench for spinning it the lenght of the threads.
Didn't use the Milwaukee wrench, returned it.

 

[Hookup1]

If it's leaking most likely it's broken. If it's a plastic thru hull you can drill out the mushroom from the outside with a step drill bit (Harbor Freight). I changed all mine last year.

 

[TLCObsession]

https://www.greatgrady.com/threads/deck-drain-scupper-surprise.28979/post-182609

The Husky spanner worked well for the tightening/loosening and the homemade 2"PVC pipe wrench for spinning it the lenght of the threads.
Didn't use the Milwaukee wrench, returned it.

View attachment 31670

I have wrenches but no room to swing them. a deep socket might allow me to use a ratchet - but I di find a post where someone used a socket and ground teh notches to grab the inside of the fitting - I think I will try that.

 

[TLCObsession]

If it's leaking most likely it's broken. If it's a plastic thru hull you can drill out the mushroom from the outside with a step drill bit (Harbor Freight). I changed all mine last year.

It is not leaking and as I said it is chrome plated bronze. I can see where there is a less than 1 mm gap to the hull. My guess is what ever sealnt was used becase hard and shrank.

 

[seasick]

There is a plumber's tool called a spud wrench. It has multiple sections of increasing diameters that mar (probably will) fit the inside of the thru and grab onto the inside 'fingers'. Available at Home Depohttps://www.homedepot.com/p/PLUMBERS-EDGE-Spud-Wrench-PE8618/300198954?mtc=SHOPPING-BF-CDP-BNG-D26P-026_002_AIR_CIRC_ACC-NA-NA-NA-PLALIA-NA-NA-NA-NA-NBR-NA-NA-NA-2023&cm_mmc=SHOPPING-BF-CDP-BNG-D26P-026_002_AIR_CIRC_ACC-NA-NA-NA-PLALIA-NA-NA-NA-NA-NBR-NA-NA-NA-2023-71700000106036630-58700008262676758-92700075065923908&msclkid=93d7bb28b9fa16d71677de0cc58b95dc&gclid=93d7bb28b9fa16d71677de0cc58b95dc&gclsrc=3p.ds

It may or may not fit because the thru has a smaller hole in the rear than in the front. You might be able to cut off the unneeded smaller sections to allow the correct size section to insert firmly.
If you know a plumber, he or she would have one or more wrenches.

 

[DennisG01]

I've read of using two screwdrivers inserted into the thru-hull on the outside and holding them in an X pattern to wedge against the thru-hull nibs and then beign able to turn it. Never tried it, myself.

Another thought... but never tried it... what about a piece of 1/4" steel stock and then grind it down to fit inside the thru hull and then put a wrench on that?

Chromed bronze... if you're fine with losing the chrome, that thru-hull (barring something odd) should be good for many, many more years.

 

[seasick]

Sometimes, you can fit a pliers into the hole and then spread the handles to make it tight against the walls of the thru hull. Then you need a bar or something similar to hold onto the handles.
It is OK to use Marelon thrus

https://www.forespar.com/products/boat-marine-plumbing-mushroom-head-hose-barb-thru-hull.shtml.

I am a bit surprised that the fitting was leaking since most likely the rear was bedded with adhesive as well as the mushroom end.

 

[glacierbaze]

I used an old socket that fit inside the opening, notched it with an angle grinder, worked like a charm.View attachment 31673

 

[TLCObsession]

I used an old socket that fit inside the opening, notched it with an angle grinder, worked like a charm.View attachment 31673

That is what I will try. How much force did you have to apply to break it free initially? What did you rebed with?

 

[glacierbaze]

I was removing the original GW white plastic through hulls, which broke apart, and had to be removed in pieces. The socket was mostly for tightening the replacement bronze through hulls.

 

[DennisG01]

TLC, if you haven't yet done so, start spraying the nut every day with something like PB Blaster - or even heavy duty vinegar - it's available at HD/Lowes and much stronger than regular vinegar and works well to eat salt. After a few applications, then come back with the PB Blaster.

 

[Timcan]

I had the same issue on my 228 I made my own wrench with a 3/4 pvc and it got the job done.

 

[glacierbaze]

Probably comes in a T model as well.

 

[Fixit]

I had a poorly installed toilet thru hull (from the factory). the inside of the hull wasn't flat where they drilled the hole, so when the nut was tightened it cocked the thru hull. I had to re bed the inside with some epoxy putty to made surfaces parallel., then I installed a new groco bronze one. unfortunately, groco makes NPS threads and the valve I have are NPT. so I threaded the end of the thru hull to npt so they're matching threads. kind of shipty that Grady would match NPT to NPT for a seacock

 

[seasick]

Groco makes fittings for both NPS and NPT

Combo Bronze Thru Hull | GROCO

NPS NPT Combo Bronze Thru Hull | GROCO

www.groco.net

 

[Scottywotty]

I need to reseal one or more of the thru hulls on my Adventure 208. One of them has a slight gap to the hull and I am getting some water coming in. In this case it is the fish locker on the starboard side. I can get the hose off, but can't budge the backing nut. I can attack it one of 2 ways:
Get a 1.5" socket and try and get the nut off
or
Get a (expensive) thru hull step wrench, have my helper hold the nut on the inside with an adjustable wrench and try and turn the thru hull out. The chrome on teh bronze is a bit pitted, but I am not sure it is worth replacing it. I just want to rebed it with wither 4200 or Boat Life. If the problem one comes out reasonably easily, I will do the others.

Advice?
Are the step wrenches available for plumbers any different than the expensive Buck Algonquin ones?

Hi Guys,

We just bought a 1996 208, we wanted to keep it in the water but after a week noticed the bilge pump running every 20 minutes or so.
luckily we still have the trailer and were able to pull it out of the water and start working on replacing all the plastic T-Hullls.
what a job! I think it was a serious short sighted view of Grady to install plastic T-Hulls on a boat, I get cutting costs to save a nickel here or there but seriously on a part that can sink a boat? ours had all broken due to age just past the inside of the mushroom flange. On the 208 there is a 6" pie plate to work within but extremely limited movement can occur. After a couple days we finally got them all replaced but not without making several custom tools and equal busted knuckles later.

Now the question I have is what is the best way to get all of that standing water that leaked into the boat out? The biggest problem I see with this model is that the center stringer goes so low that water sits in that section and is real hard to pump out. Too many foam filled nooks and crannies in this boat to get it all out.

Thanks for any insight and advice!

Scotty

 

[glacierbaze]

Jacking the trailer all the way up will not usually be enough to clear those mid, and forward bilge areas. Assuming that your PVC drain pipes, and limber holes through the stringers are clear, parking on a steep ramp for a few minutes will get most of the water out of those areas, in many boats.
If you do try to put blocks under the jack to lift it higher, make sure your motor is up first.

 

[Fixit]

Groco makes fittings for both NPS and NPT

Combo Bronze Thru Hull | GROCO

NPS NPT Combo Bronze Thru Hull | GROCO

www.groco.net

unfortunately they are not an NPT thread despite being advertised as such..... what they do is grind a 1.8 degree taper -same as NPT taper into the NPS threads. (the tips of the threads are ground down). while this improves the fit slightly, and does give you one extra thread of engagement its not the same. (you get 2, maybe 2.5 threads engagement with grocos "NPTish" while a true NPT engagement is more like 5 or 6 threads. it is better than the one thread engagement you get with a NPT to NPS mismatch

 

[DennisG01]

unfortunately they are not an NPT thread despite being advertised as such..... what they do is grind a 1.8 degree taper -same as NPT taper into the NPS threads. (the tips of the threads are ground down). while this improves the fit slightly, and does give you one extra thread of engagement its not the same. (you get 2, maybe 2.5 threads engagement with grocos "NPTish" while a true NPT engagement is more like 5 or 6 threads. it is better than the one thread engagement you get with a NPT to NPS mismatch

You could have used a flanged adapter by Groco. It's straight thread on the inside (bottom) and NPT on the outside (top). Plus, because of the flange, it's a much more secure way to install seacocks/etc. The ideal way, and I don't know why Grady doesn't do this, is to first glass a block onto the hull, then screw down the flange adpater onto the thru-hull and then screw the flange to the block. Everything is MUCH more secure that way. Plenty of other manufacturers do this.

I, honestly, didn't even know you could change straight threads to NPT. Does that compromise anything by making the pipe/thread thinner?