I just purchased a 1988 Catalina 30. It has a cracked through hull. I was told these are easy to cahnge. Can anyone give me advice on how to change one? Thanks, Brad
changing a plastic through hull
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First of all take the boat out of the water
Next buy a new thru-hull of the size you will need. Have someone on the outside of the boat with a proper tool to prevent the thru-hull from turning while you struggle with the nut on the inside. After you have removed the nut, you push the old thru-hull out and clean up the surfaces. Next you apply your favorite BELOW THE WATERLINE bedding compound to the flange and have your helper push the thru-hull back into the hole. You should at this time be inside with the nut and a proper wrench to tighten the nut. Reconnect the hoses with TWO(2) hose clamps .
Next buy a new thru-hull of the size you will need. Have someone on the outside of the boat with a proper tool to prevent the thru-hull from turning while you struggle with the nut on the inside. After you have removed the nut, you push the old thru-hull out and clean up the surfaces. Next you apply your favorite BELOW THE WATERLINE bedding compound to the flange and have your helper push the thru-hull back into the hole. You should at this time be inside with the nut and a proper wrench to tighten the nut. Reconnect the hoses with TWO(2) hose clamps .
I agree with Ross, but add, sometimes
the thru-hull can be worked on with only one person from the inside with the same tools. The cleaning etc., Just like Ross described. If you have the option of a second person, it is easier. r.w.landau
the thru-hull can be worked on with only one person from the inside with the same tools. The cleaning etc., Just like Ross described. If you have the option of a second person, it is easier. r.w.landau
Make sure you have a helper for a proper job.
Through hulls must be removed and installed absolutely correctly or you will end up with a problem. It is not a one man job - get help and do it right!
Through hulls must be removed and installed absolutely correctly or you will end up with a problem. It is not a one man job - get help and do it right!
First of all
Is this above or below the water line? If it is above the water line and does not get dunked you can probably replace these on a calm day. If it is below the water line and is cracked and leaking ya better get it out quick before she sinks.......My opinion. I am replacing all of mine; above and below the water line. The above water line ones that are typiocally a plastic like material on all boats were pretty simple to remove. The person who bed the original ones did a great clean job. Looking at the below water line ones, they also look cleanly done and hopefully will also come out easy. On my last boat, I had to cut the below water line ones out as they were severely corroded. Love my recircular saw! Taking these out can be done by one person, but to get a real good rebedding job, I will take the help to get it done right. Bedding compound goop can get everywhere real quick and make a giant mess (yes some people are surgically gifted and can do it). From what I have learned put the stuff where it belongs and don't cover the threads. Quality not quantity! And yes, the correct tool makes the world of difference. Good luck! Greg
Is this above or below the water line? If it is above the water line and does not get dunked you can probably replace these on a calm day. If it is below the water line and is cracked and leaking ya better get it out quick before she sinks.......My opinion. I am replacing all of mine; above and below the water line. The above water line ones that are typiocally a plastic like material on all boats were pretty simple to remove. The person who bed the original ones did a great clean job. Looking at the below water line ones, they also look cleanly done and hopefully will also come out easy. On my last boat, I had to cut the below water line ones out as they were severely corroded. Love my recircular saw! Taking these out can be done by one person, but to get a real good rebedding job, I will take the help to get it done right. Bedding compound goop can get everywhere real quick and make a giant mess (yes some people are surgically gifted and can do it). From what I have learned put the stuff where it belongs and don't cover the threads. Quality not quantity! And yes, the correct tool makes the world of difference. Good luck! Greg
Bronze or Stainless
?? ?? to NYSAIL, What material is better for these thru, Bronze or Stainless Steel @ why ???? Grigs
?? ?? to NYSAIL, What material is better for these thru, Bronze or Stainless Steel @ why ???? Grigs
Change out in the water
On a small to medium size boat, if the thru hull is within a foot or so of the resting water line , you can use a halyard and snatch blocks to heel the boat in the slip until the thru hull is above the water. Once you have the thru hull out of the water a person in the dingy holds the special wrench/fitting to keep the thru hull from turning while you remove the backing nut from the inside. I've done it on my 28.5 on the galley thru hull with no problems at all. It took longer to set up the halyard and dock lines to heel the boat than it did to replace the thru hull. Make a point of checking all the seacocks, valves and thru hulls while the boat is on the hard and do it the easy way while you can.
On a small to medium size boat, if the thru hull is within a foot or so of the resting water line , you can use a halyard and snatch blocks to heel the boat in the slip until the thru hull is above the water. Once you have the thru hull out of the water a person in the dingy holds the special wrench/fitting to keep the thru hull from turning while you remove the backing nut from the inside. I've done it on my 28.5 on the galley thru hull with no problems at all. It took longer to set up the halyard and dock lines to heel the boat than it did to replace the thru hull. Make a point of checking all the seacocks, valves and thru hulls while the boat is on the hard and do it the easy way while you can.
NYSail, Good point. Putting the bedding/caulking/
sealant, in the right place. Remember that you are not trying to seal inside out, you're sealing outside in. The important thing is where that the seal is, and it shoud be from the outside in. Since I have never had help installing thru-hulls for myself or while repairing boats, I have learned that you apply the bedding material on the thru-hull around the flange. Then from below, push the thru-hull into the hole until the sealant holds it inplace. Do not press it all the way tight to the hull. Let the install process do that. The bedding compound will hold it there while you climb back inside and start the interior nut by holding the threaded portion inside while you start the nut. Then insert a tool into the hole of the thru-hull to keep it from spinning. This tool is anything that keeps it from spinning. Each thru-hull size will require a different tool to keep it from spinning. Then tighten the interior nut. Go outside with a finger and clean the excess bedding material from the flange of the thru-hull. Have some 3M caulking remover on hand to clean your fingers and any really messy boat parts. It can be done with one man. I have done 8 of my own on my boats and probably four time that for other peoples boats. If your thru-hull spins, it will increase the chances of a leak. One thing that I do that I would not recommend if you don't undersatnd, is to counter sink the exterior hole slightly. This gives he sealant thickness that is needed for it to work more affectively. I do every thing in bronze. r.w.landau
sealant, in the right place. Remember that you are not trying to seal inside out, you're sealing outside in. The important thing is where that the seal is, and it shoud be from the outside in. Since I have never had help installing thru-hulls for myself or while repairing boats, I have learned that you apply the bedding material on the thru-hull around the flange. Then from below, push the thru-hull into the hole until the sealant holds it inplace. Do not press it all the way tight to the hull. Let the install process do that. The bedding compound will hold it there while you climb back inside and start the interior nut by holding the threaded portion inside while you start the nut. Then insert a tool into the hole of the thru-hull to keep it from spinning. This tool is anything that keeps it from spinning. Each thru-hull size will require a different tool to keep it from spinning. Then tighten the interior nut. Go outside with a finger and clean the excess bedding material from the flange of the thru-hull. Have some 3M caulking remover on hand to clean your fingers and any really messy boat parts. It can be done with one man. I have done 8 of my own on my boats and probably four time that for other peoples boats. If your thru-hull spins, it will increase the chances of a leak. One thing that I do that I would not recommend if you don't undersatnd, is to counter sink the exterior hole slightly. This gives he sealant thickness that is needed for it to work more affectively. I do every thing in bronze. r.w.landau
The thru-hull tool is nice to have
Buck Algonquin makes a tool intended for holding thru-hulls which works for everything from 1/2 up to 1 1/2 inch thru-hulls. It cost something like 30 dollars and makes it really easy to remove them and it’s useful for installing them. All the best, Robert Gainer
Buck Algonquin makes a tool intended for holding thru-hulls which works for everything from 1/2 up to 1 1/2 inch thru-hulls. It cost something like 30 dollars and makes it really easy to remove them and it’s useful for installing them. All the best, Robert Gainer
Maybe this comes from the woodie days.
When dealing with any fittings on deck, hull above waterline or below. Stuffing boxes prop shaft struts or rudder brackets I'll use 3-M 4200 or 5200 depending. Both caulked surfaces have to be clean and free of previous caulk,( using a little heat works great on removing 5200). Caulk the fitting and install but do not tighten just snug it up you don't want all the caulk to ooozz out. Clean up and go back a couple days later and tighten it. this way you get a good tight seal. In the case where there are nuts and bolts as in a drive shaft strut, after the caulk sets a few days pull the bolts out an caulk both bolt and holes and tighten them up while caulk is pliable.
When dealing with any fittings on deck, hull above waterline or below. Stuffing boxes prop shaft struts or rudder brackets I'll use 3-M 4200 or 5200 depending. Both caulked surfaces have to be clean and free of previous caulk,( using a little heat works great on removing 5200). Caulk the fitting and install but do not tighten just snug it up you don't want all the caulk to ooozz out. Clean up and go back a couple days later and tighten it. this way you get a good tight seal. In the case where there are nuts and bolts as in a drive shaft strut, after the caulk sets a few days pull the bolts out an caulk both bolt and holes and tighten them up while caulk is pliable.
Chuck, I agree if you have the time.
Robert, I have never had the luxury of buying a proper tool for thru hull. I have had to make my own tools. The tool is usually just a blade that fits through the thru-hull fitting that catches on the internal nubs. For smaller thru hulls, I have used large screw drivers. For 1 1/4 thru hulls I have cut 1/4 " stainless to use as a key. Tools are nice but the improv works just as well if the thru-hull does not spin. r.w.landau
Robert, I have never had the luxury of buying a proper tool for thru hull. I have had to make my own tools. The tool is usually just a blade that fits through the thru-hull fitting that catches on the internal nubs. For smaller thru hulls, I have used large screw drivers. For 1 1/4 thru hulls I have cut 1/4 " stainless to use as a key. Tools are nice but the improv works just as well if the thru-hull does not spin. r.w.landau
Use a plastic through hull.
There are fibre filled plastic through hulls that are strong enough to use below the water line. No electrolysis. There is a stainless ball in the ball valve, but it's pretty isolated in the nylon bearing. Condisering the froth over SS vs Bronze on the other thread, I look forward to this one.
There are fibre filled plastic through hulls that are strong enough to use below the water line. No electrolysis. There is a stainless ball in the ball valve, but it's pretty isolated in the nylon bearing. Condisering the froth over SS vs Bronze on the other thread, I look forward to this one.
look in the plumbing section
the tool Ross is talking about is used to hold sink drains from turning and might work well-good idea Ross!
the tool Ross is talking about is used to hold sink drains from turning and might work well-good idea Ross!
Ross and Chuck, Thanks, I actually like
my home made tools. They are definately specialized tools but for someone that doesn't have that kind of stuff laying around to make stuff, your ideas are great ideas! Point is don't let the thru-hull turn! As a contractor I am a big box regular and if I can spend ten minutes making something, I love avoiding the 45 minute round trip plus the hunt time that I spend daily at the big box. Again, back to the original post, as you can see, many opinions, many proceedures. Choose your pick... they will all work, some people get crazy, myself included. Look at your situation to make the choice that you think will work for you. I still like bronze! r.w.landau
my home made tools. They are definately specialized tools but for someone that doesn't have that kind of stuff laying around to make stuff, your ideas are great ideas! Point is don't let the thru-hull turn! As a contractor I am a big box regular and if I can spend ten minutes making something, I love avoiding the 45 minute round trip plus the hunt time that I spend daily at the big box. Again, back to the original post, as you can see, many opinions, many proceedures. Choose your pick... they will all work, some people get crazy, myself included. Look at your situation to make the choice that you think will work for you. I still like bronze! r.w.landau
some of the special tools
R.W., The biggest reason for a shop to have some of the special tools is so they can justify the price for the job. If I don’t have my thru-hull tool handy I use the handle of an appropriately sized crescent wrench. I always have those handy. Plastic is fine in some applications such as on a aluminum boat and they don’t have any less strain on them then on a fiberglass boat. But for the small price difference between the bronze and plastic thru-hull I would just prefer the bronze. Also I should mention that plastic above the water line is attacked by ultraviolet unlike bronze and it will degrade after a while. I just pulled the plastic bilge pump thru-hull out on the company boat and it fell to dust. I think it was about twenty years old. All the best, Robert Gainer
R.W., The biggest reason for a shop to have some of the special tools is so they can justify the price for the job. If I don’t have my thru-hull tool handy I use the handle of an appropriately sized crescent wrench. I always have those handy. Plastic is fine in some applications such as on a aluminum boat and they don’t have any less strain on them then on a fiberglass boat. But for the small price difference between the bronze and plastic thru-hull I would just prefer the bronze. Also I should mention that plastic above the water line is attacked by ultraviolet unlike bronze and it will degrade after a while. I just pulled the plastic bilge pump thru-hull out on the company boat and it fell to dust. I think it was about twenty years old. All the best, Robert Gainer
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