Arrggg...bloody blue drain plugs !

[QBhoy]

Can someone please tell me what witchcraft is at work with regards to the Merc blue drain plugs ?
I have one on the T Stat. Every spring I tighten it just less than hand tight....and every winter it magically seems to have accumulated a torque tighten figure of unimaginable quantity. Enevitably each year I try and carefully undo it with a tight fitting adjustable spanner over as much surface area of the lugs as possible...and every year I snap the bloody thing and end up with a screwdriver and hammer knocking it undone...
Is it just me ?

 

[Scott Danforth]

They are a failed design. Plasic creep causes the plug to weld itself in the adapter

Best thing to do, get the stainless aftermarket ones ore replace with good old fashioned plugs

 

[QBhoy]

Brilliant Scott.
I?ve actually read of this solution before, now I think of it. I suppose I just liked the look of the fancy wee blue plug and the lack of tools required to drain....but I?ve now had enough ! Proper threaded metal plug it is !
Does the same happen when the blue plugs are fitted on the manifolds and block ? What a nightmare that must be. All my old engines had metal plugs.
The blue plugs ain?t cheap either !

 

[Lou C]

That is not one of their better ideas! Id replace all of them with metal plugs as used on OMCs and Volvos. Mine are original 30 years old I just put a bit of OMC gasket sealer or Permatex Aviation sealer and they always come out even with salt water use.

 

[QBhoy]

Thanks Lou. I?ll replaxe the TStat plug with a proper one come the spring.

 

[Lou C]

My new Barr exhaust manifolds came with nice big pipe plugs that have a 3/8ths recess in them so you use a regular 3/8ths ratchet to remove them; very easy....

 

[Scott Danforth]

There are stainless replacements for just the blue plug

http://www.michiganmotorz.com/stain...MI6Oqx-bOn1wIVhVqGCh2SsQaAEAQYAiABEgKbnvD_BwE

 

[alldodge]

Can someone please tell me what witchcraft is at work with regards to the Merc blue drain plugs ?
I have one on the T Stat. Every spring I tighten it just less than hand tight....and every winter it magically seems to have accumulated a torque tighten figure of unimaginable quantity. Enevitably each year I try and carefully undo it with a tight fitting adjustable spanner over as much surface area of the lugs as possible...and every year I snap the bloody thing and end up with a screwdriver and hammer knocking it undone...
Is it just me ?

Folks appear to have more trouble with them in salt water. I have never had one snap and are easy enough to remove. Was replacing them every few years but them went to the Hardin marine SS. Did find they work nicely in the brass fittings, but could not get them to screw into the plastic exhaust manifold fittings. Has something to do with how the threads are cut, juts guessing, so still use the blue in those two positions

 

[nazmen1]

If replacing with brass plugs what is the size and thread?

 

[Bondo]

Ayuh,.... 1/2"- 13,....with an o-ring seal,....