I will be replacing the knotmeter & sounder on RESPITE (very soon). Both transducers will need to be replaced. While the holes in the hull are the right size, the thru hulls need to be removed, with minimal damage to ship & technician (me).
I am seeking advice from those who have traveled this path before me. What was the most likely bonding agent (5200?)? What can I do to ease the removal and prep for the new install?
I will also be installing a Raymarine (nee Auto Helm) ST4000 Wheel Pilot. If you have installed one, your helpful hints would be appreciated.
Every Best Wish,
Mitchell Bober
RESPITE
CD330
Nasty Business--Removal of thru hull fittings--HELP
Moderator: Jim Walsh
-
Bristol Bronze
Re: Nasty Business--Removal of thru hull fittings--HELP
Dear Mike,M. R. Bober wrote: I will be replacing the knotmeter & sounder on RESPITE (very soon). Both transducers will need to be replaced. While the holes in the hull are the right size, the thru hulls need to be removed, with minimal damage to ship & technician (me).
I am seeking advice from those who have traveled this path before me. What was the most likely bonding agent (5200?)? What can I do to ease the removal and prep for the new install?
I will also be installing a Raymarine (nee Auto Helm) ST4000 Wheel Pilot. If you have installed one, your helpful hints would be appreciated.
Every Best Wish,
Mitchell Bober
RESPITE
CD330
The worst part of trying to remove your thru-hulls is usually the bedding compound/adhesive that was used. Since the intent of the persons who installed them was to keep them in place 3M 5200 may well have been used. It is an excellent adhesive but does have one weakness.......heat.
Use a heat gun, not an open torch or flame. As you heat the fitting the 5200 (and most other adhesives as well) will begin to get softer. Now have a friend apply gentle but constant pressure to the nut with a wrench. After a turn or so you can probably slip a thin knife blade between the metal fitting and the hull and help break more of the bond of the adhesive. I have used 5200 for years and never had a problem getting things off again when I used a little heat.
Roger W.
Bristol Bronze
401-625-5224
rogerw@bristolbronze.com
-
matt cawthorne
Re: Nasty Business--Removal of thru hull fittings--HELP
Mitch,
I did my knot meter through hull a few years ago. It is really quite simple, even if done with 3m-5200. You will need a few 2x4's or 2x6's, a piece of all-thread, some nuts and some big washers. Remove the transducer. Drill a hole in a 6 inch piece of 2x4 that that your all-thread will pass through. Put the all-thread through from the outside of the boat, through the wood, through a large fender washer and then put a nut and lock nut on. Do the same on the outside of the boat with a 1 foot long piece of wood, but no lock nut. Slip two pieces of 2x4 on their side under the ends of the 2x4 on the outside of the boat. The 2x4 on the outside bridges the through hull, but just barely. Now have someone hold the nut on the inside of the boat with a wrench and you crank on the nut on the outside. This arrangement will jack out the through hull fitting. By the time the 2x4 on the inside of the hull hits the hull the sealant is all broken free and the unit can be disassembled. It goes pretty fast. I had tried other techniques for hours before deciding on this one. Even without someone on the inside to hold the nut I was able to use this technique to get the fitting out in about 15 minutes. The trick there is to put 3 nuts on the outside of the boat. One to crank on the all thread, and two on the end of the all-thread jammed together to hold the all-thread from turning. Make new backing plates out of marine plywood, and use several coats of epoxy to seal the wood. Use masking tape when installing the new fitting and backing plate. It makes cleanup much more simple.
Matt
mcawthor@bellatlantic.net
I did my knot meter through hull a few years ago. It is really quite simple, even if done with 3m-5200. You will need a few 2x4's or 2x6's, a piece of all-thread, some nuts and some big washers. Remove the transducer. Drill a hole in a 6 inch piece of 2x4 that that your all-thread will pass through. Put the all-thread through from the outside of the boat, through the wood, through a large fender washer and then put a nut and lock nut on. Do the same on the outside of the boat with a 1 foot long piece of wood, but no lock nut. Slip two pieces of 2x4 on their side under the ends of the 2x4 on the outside of the boat. The 2x4 on the outside bridges the through hull, but just barely. Now have someone hold the nut on the inside of the boat with a wrench and you crank on the nut on the outside. This arrangement will jack out the through hull fitting. By the time the 2x4 on the inside of the hull hits the hull the sealant is all broken free and the unit can be disassembled. It goes pretty fast. I had tried other techniques for hours before deciding on this one. Even without someone on the inside to hold the nut I was able to use this technique to get the fitting out in about 15 minutes. The trick there is to put 3 nuts on the outside of the boat. One to crank on the all thread, and two on the end of the all-thread jammed together to hold the all-thread from turning. Make new backing plates out of marine plywood, and use several coats of epoxy to seal the wood. Use masking tape when installing the new fitting and backing plate. It makes cleanup much more simple.
Matt
mcawthor@bellatlantic.net
-
Ed Haley
Re: Nasty Business--Removal of thru hull fittings--HELP
Hi, Mitch:
I installed an Autohelm 4000 Wheel Pilot on my CD28 a few years back. Aside from picking a useful spot to place the control head and selector box, the most critical element was placing the field sensor away from the engine as far as possible and as close to the midline as you can get it. I positioned mine beneath the port settee as far forward as I could get it on a vertical athwartship wall. At first I installed it on the aft end but this was too close to the engine (the large mass of iron effected the sensitivity of the unit). It worked well at the forward wall. This was 8 feet from the engine.
When I installed the motor on the pedestal, I routed the wires up the inside of the pedestal and through a hole at an appropriate spot. The motor mount on the pedestal was easy but the solid metal finger that goes into the drive wheel must be cut to the right length. If it's too short, you'll need to get another and try again.
These remarks are based on the assumption that the newer wheel pilot has essentially the same mounting hardware.
All in all, in general, it was the best piece of equipment I could have added.
eghaley@twcny.rr.com
I installed an Autohelm 4000 Wheel Pilot on my CD28 a few years back. Aside from picking a useful spot to place the control head and selector box, the most critical element was placing the field sensor away from the engine as far as possible and as close to the midline as you can get it. I positioned mine beneath the port settee as far forward as I could get it on a vertical athwartship wall. At first I installed it on the aft end but this was too close to the engine (the large mass of iron effected the sensitivity of the unit). It worked well at the forward wall. This was 8 feet from the engine.
When I installed the motor on the pedestal, I routed the wires up the inside of the pedestal and through a hole at an appropriate spot. The motor mount on the pedestal was easy but the solid metal finger that goes into the drive wheel must be cut to the right length. If it's too short, you'll need to get another and try again.
These remarks are based on the assumption that the newer wheel pilot has essentially the same mounting hardware.
All in all, in general, it was the best piece of equipment I could have added.
eghaley@twcny.rr.com
-
mike
Re: Nasty Business--Removal 5200
On this subject. I've noticed a new product in the West Marine cataloge for removing 5200. Has anyone tried it?
-
Boyd
Re: Nasty Business--Removal 5200
Yep... used it to remove the pumpout fitting in the cockpit floor. Works well. It actually softens and partially disolves the 5200. No damage to gelcoat at all. Kind of messy cleanup. Spray on and go away. Come back and spray again. Go away. Come back in about 15 minutes and the fitting should move.
Boyd
Tern30@aol.com
Boyd
mike wrote: On this subject. I've noticed a new product in the West Marine cataloge for removing 5200. Has anyone tried it?
Tern30@aol.com