drain plug fit

[jim_m5]

OK. I took out my garboard drain plug and cleaned the engine bilge. I also have the oil-drain hose connect to the external drain plug. I tried to put the drain plug back in but it only screws in half-way. I pulled out and tried to clean with a wire braush thinking there was gook in the trheads, but no luck. It does not seem to leak but I still would like to get in further. Has anyone had this problem? Appreciate any advice.

 

[jg300da]

It's not supposed to go all the way in flush as it is a tapered thread. The further in it goes the tighter it gets. Use some teflon tape on the threads and snug it up. Done.

 

[tginz]

Drain plugs have an NPT - National Pipe Thread. It progressively gets a tighter thread from the leading threads inward - therefore it gets tighter as it goes in. Mine goes about half way. This NPT eliminates the need for teflon tape or pipe dope. Most of your engine fittings are the same way. Did FWC last winter and found every plumbing thread was an NPT.

 

[Stray Cat]

Per the authority on fittings, Parker Hannifin, for 1/2 in. steel, stainless steel, or brass tapered pipe thread is 2 or 3 turns from finger tight with a properly applied thread sealant.

 

[jg300da]

This NPT eliminates the need for teflon tape or pipe dope.

I'm going to respectfully disagree here. The taper does not preclude the need for teflon tape/pipe dope. Maleable plumbing fittings like those used for water and gas piping use tapered fittings and they are always used with some type of thread sealant.
I use teflon tape because it allows me to seal the fitting without overtightening and makes the plug easier to remove at the end of the season.

 

[tginz]

I should have qualified my statement to "in the case of these drain plugs I feel teflon tape is not necessary". I agree that "permanent" fittings should have tape or sealant and when installing my freshwater cooling system I use Mercury Perfect Seal on all NPT fittings. That said, I install and remove my drain plug daily because I'm trailered. Out of curiosity, I've looked and haven't found trace of water around the plug without tape, but I surely would not trust a fitting to stay watertight with anything above hull pressure.

Thanks for the correction and point well taken.:thumbsup:

tginz

 

[Woody]

I should have qualified my statement to "in the case of these drain plugs I feel teflon tape is not necessary". I agree that "permanent" fittings should have tape or sealant and when installing my freshwater cooling system I use Mercury Perfect Seal on all NPT fittings. That said, I install and remove my drain plug daily because I'm trailered. Out of curiosity, I've looked and haven't found trace of water around the plug without tape, but I surely would not trust a fitting to stay watertight with anything above hull pressure.

Thanks for the correction and point well taken.:thumbsup:

tginz

Just wondering why you pull the transom plug daily? Do you actually get water in the bilge each time you use the boat?

 

[tginz]

Typically, my useage is every weekend or every other weekend. Therefore, I drain the water tank and hot water tank into the bilge. I open both at the ramp, pull the plug and my tow load gets lighter on the way home...:smt038 Water weights about 8.36-lbs/ gal.

If I leave the water in the hot water tank, specifically, it gets S T I N K Y and no one will use the hot water. :smt089 A fresh fill of water each week and no smell. I could pump over the side but the water in the bilge rinses through dust and dirt that ends up in the very bottom. The only time I take in water is from one: washing the cockpit and water enters around the engine hatch latch or two: in a beam sea and I get constant spray into the rear air vents. Otherwise the bilge is dry as a bone. I like to start out completely dry so I can monitor any issues from the outdrive bellows. :thumbsup:

 

[boatmailster]

Just wondering why you pull the transom plug daily? Do you actually get water in the bilge each time you use the boat?

It is a good idea. It prevents from collecting any rain water and helps keep bilge dry.