1996 Crestliner plug leak?

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Givey1982

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Location
Oklahoma
LOCATION
Oklahoma
I bought this 96 Crestliner and finaly got it out on the water today. It has a screw in plug in the bottom of the boat which i believe is leaking. I did notice the leak initially so I cannot promise that is where it is coming from. There is a rubber washer the previous owner had made to go on it but my dad still thinks that may be the problem. I did tighten it with pliers pretty good but there us still a leak. Has anyone else experienced this problem with a screw in plug?

Thanks
 
Givey, with the boat on the trailer, tilt it up from the front
and put a few inches of water in the back to see where the leak might be.........
if the plug doesn't leak, then you go from there
with the same process of more water in the boat
with the trailer level and do more investigation.
from underneath the boat, mark each leaker with a marker.
drain the water and address the leak issue.

if the threads appear to be smoothed out, take a
1/2" pipe nipple and try to dress up the threads.
if the threads are completely gone, that is another issue.

- and - how much water are you talking about ?
 
Johnny said:
Givey, tilt your boat up from the front and
put a few inches of water in the back to see
where the leak might be.........
if the plug doesn't leak, then you go from there
with the same process of more water in the boat
with it level and do more investigation.

if the threads appear to be smoothed out, take a
1/2" pipe nipple and try to dress up the threads.
if the threads are completely gone, that is another issue.

- and - how much water are you talking about ?
 
Does anyone else have a drain plug that screws into the bottom of the boat? Filling the boat with water does not show a leak. When the boat is in the water with the applied water pressure is when it leaks. I don't know if these came with a gasket or not when they were manufactured or not. They guy I bought the boat from said he had a hard time getting it to not leak so he added the washer. It still leaks about 2 gallons in about 45 minutes.
 

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Edit: upon magnifying your image, I notice that there may be
damage to the area where the black arrow points.
the uneven wear pattern from the gasket (yellow and orange lines) indicates a
less than even seal . . . the threads could be the culprit - not the plug. your plug looks normal.
The old style plugs are normally galvanized iron or steel and are much harder than the soft aluminum drain.
I remember my father (in 1960) throwing that plug into the orange grove and replacing it
with a brass plug - because the original plug rusted.... that is when I learned to use the brass plug.
in the worse case scenario, the threads may have been stripped by cross threading.
you may need to have a plumber run his thread chaser through it. or, find a cheap 1/2" pipe tap.
drain.jpeg
image.jpeg

.

The type of vintage plug you have is very common for that style of drain.
I have two 1959 boats now that have the 1/2" NPT threaded hole.
I do not use the plug with the gasket, I use the standard 1/2" plumbing brass plug
with zero leakage. Available at any big box store for about $4 ($7 at BPS).
Brass Plug.jpg
try this one - I know it does not have the handy finger-twist top but,
if it doesn't leak, it may be worth the wrench time.

if your plug is the 1/2" size, find a short 1/2" pipe with threaded ends and rework
the threads in your boat drain.
last option would be to load up the plug threads with teflon tape. that will only last a few trips.
Pipe Nipple.jpg

if you choose to try to repair it yourself, I found a 1/2" NPT tap on the Sears website for $5.60.
$24 at Lowe's and NAPA. shop around.
Note: Pipe threads are different than your normal standard bolt threads.
Pipe threads are tapered to ensure a good leakproof seal.
so if you run the standard 1/2" bolt tap into your drain, it will not work.
pipe tap.JPG

last final resort would be to remove the existing drain completely and
install a flat brass threaded drain with the plug as you have now.
- or - close up the old drain and install the drain pipe with the external plug.
613.jpg


please let us know what you did after you fix it.



.
 
Thanks a lot for the information. I did not realize it might be pipe thread. A lot of options open up now.

Thanks again
 
from my first response "if the threads appear to be smoothed out, take a
1/2" pipe nipple and try to dress up the threads.
if the threads are completely gone, that is another issue".


to check the female threads, gently screw a piece of the 1/2" threaded pipe into it.
if the threads are gone, you will know it fairly quickly.

good luck !!




.
 
Looks like it is likely 3/4". All I have is a PVC piece which does not thread in. 1/2 slides right through. I will pick up a galvanized 3/4" nipple tomorrow and try it to be certain.
 
it is 1/2" NPT (National Pipe Thread).

I just checked my '59 Crestliner and it is 1/2" and the brass plug fits tight.
Then, I checked the Lone Star I bought a few months ago and
just now getting to work on it - - - guess what ???
it also takes the 1/2" plug but the female threads are stripped just like yours.

the 3/4" PVC fitting is too big and the 1/2" PVC fitting is way too loose.
so now I find myself in the same boat as you (pun intended).
when I bought the boat, I noticed the drain had the expanding rubber stopper
in it - - - I thought it was just because he lost the brass plug or something.
now - I understand - the threads are stripped and thus the rubber plug.
My line of thought is to enlarge the hole to accept a 3/4" brass pipe plug. (less hassle).

for now, you can use the expanding rubber plug. (I personally don't trust the flip handle style of plug).
boat plug (2).jpg

I just bought a 3/4" tap off of ebay for $12....... that seems like the cheapest and easiest option.
34.jpg





.
 
Have you had good luck with the expandable stopper type in the bottom of the boat?
 
I have never used a stopper in a threaded drain.
I have not had the Lone Star in the water yet.
I just found out this afternoon that the threads were stripped just like yours.
in theory, yes, it will work. Only way to know if
it fits your application is to find a 1/2" rubber stopper and give it a try.
I have used the rubber stopper in the transom drain "tube" round pipe with no issues.
and again, I prefer the twist type vs the flip handle stopper.
 
Johnny has given all the tips of how to fix. My question is, Is the hole actually a drain for the boat or is it in the livewell to feed it? Your threaded plug and gasket look like mine for my gravity fed livewell in a 1997 Gen 3 boat. Mine has a gasket and seals good. Yours looks like it needs a fix or repair as Johnny outlined. Just curious of what the hole is for?
 
Hey Givey - I had the plan to retap the hole to a 3/4"
and ordered the 3/4" NPT pipe tap off of ebay.
got the tap yesterday, and, looking at just how much
material must be removed, it leaves very little "meat"
surrounding the threaded part of the hole........
so, I am going to abandon that idea for now and go with
the Permatex Thread Repair kit which I have used before
and have confidence in it....... also, reinforce the outside
of the hole wall with 2-part epoxy putty.
you asked about the rubber plug - yes, it will also work if you can
find a 1/2" and you can get it to seat correctly.

https://youtu.be/B3WxsZxLqi0
also https://youtu.be/zUI6GMkTOjU
 
Is this what you are talking about?

https://youtu.be/B3WxsZxLqi0

If so I guess we put a piece of tape on the bottom side of the boat, fill the hole and screw our existing plug in? I assume this works for aluminum since you have used it before.

Thanks
 
yes - that is the one I used for restoring threads in a 1958 Johnson outboard lower unit.
I am sure there are many epoxy products on the market, such as JBweld
that will probably work just as well.
remove as much corrosion and oxidation as you can and run a Q-Tip
in the threads with muriatic acid to remove any remnants of oxidation.
rinse well - follow up with baking soda wash - rinse well - do your repair
with whatever product you choose to use.
 
Johnny

Did you get your plug fixed? As it is warming up here now I am getting ready to try something. I am going to try pipe compound first with the existing washer. If that does not work I am going to try your method. If it does not work I am considering sealing it and adding a drain in the transom.

Thanks for all of the experience you share here on the forum

Greg
 
Greg - I used the epoxy thread repair kit and it seems to be
holding its own so far. (I don't over-torque it).

I really think your threads are stripped in the drain and must
be built up to be repaired with epoxy or welded and retaped
your last option is like you said - seal it off and put in a new drain.
Drain Plug Repair 024.JPG
Drain Plug Repair 027.JPG
Drain Plug Repair 028.JPG
 
I had a leak in my 2012 Crestliner Retriever. Turned out the boat took in water under the caps that join the transom and the gunnels. At the corners of the transom of the boat, on top. Hope that makes sense. Every time I slowed the boat down quickly or made a sharp turn, the water would was up against the outside of the transom, and the ensuing "wave" would go up and under the corner cap and flow into the boat. Took a while for the dealer to find that problem, but once he did and once he caulked under the end caps, no more water came into the boat.
 
Johnny said:
Greg - I used the epoxy thread repair kit and it seems to be
holding its own so far. (I don't over-torque it).

I really think your threads are stripped in the drain and must
be built up to be repaired with epoxy or welded and retaped
your last option is like you said - seal it off and put in a new drain.
View attachment 2
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Nice job Johnny
I am a couple of weeks away from trying this but I agree about the threads and will give this a shot.

Thanks
Greg
 

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