Carver Cascade 2 Drain Plug

[Jim_374473646]

I have an early version of the Cascade 2 that used the imperial BSP thread plug.

I bought a replacement from fleabay, the replacement is a brass one rather than plastic, which I believe the original was (it was missing when I got the caravan). It is definitely the early model (1986) as I first got a newer plastic metric plug which is too small.

Anyhow back to the point in question. The new plug is extremely tight, the threads in the "pipe" seem a bit grubby. How can I clean them?

Jim

 

[Parksy]

Hi Jim

How about trying a cotton bud soaked in white spirit or WD40?

 

[Damian]

Jim, either buy or hire a 1/2 inch BSP taper tap and gently run it through, or a more gentle way is use a 12 bore gun barrel cleaner, available from any good gun shop

 

[Jim_374473646]

I had a brain wave.

I used my Dremmel with a wire "chimney sweep" type brush on it.

Worked a treat

Jim

 

[Gav]

good tip, ive got the same heater and ive got a dremmel!!! will be looking at that when the cold weather comes!

 

[ProfJohnL]

Hello Jim,

The main body of the Cascade is made from aluminium. It is not recommended to use brass or copper fittings in waterways where both metals come into contact. Electrolytic corrosion will almost certainly start up. It will tend to 'weld' the fitting in place making it difficult to remove at the ends of the season , and the free copper ions released from the brass will initiate tunnelling corrosion on any weak points in the tanks anodising.

 

[Jim_374473646]

Thanks for the tip John.

I'll see if I can get hold of the nylon one.

Jim

 

[Damian]

Whilst I agree with John L, that in normal circumstances disimmilar metals should not be used, in this instance there is no other choice.

The drain plugs available are metric, the old style BSP are not available anywhere now, unless you happen to find one on an old cascade unit.

 

[gary]

hold the phone, I may well have the ideal solution tomorrow????

 

[Jim_374473646]

I await Gary's reply tomorrow.

I have searched the net and can't find any of the nylon ones :-(

How long would it take for a problem to manifest with the dissimilar metals, after all the heater is now ~23 years old?

Jim

 

[JTQ]

The drain plug definitely should not be brass and the body is not threaded BSP.

I made my own tap to "clean" up the body thread; however if I recall correctly it is the same thread as a towing bracket bolt [16mm].

So buy the correct plastic plug and a towing bracket bolt.Ideally file a small flat on the bolt making it into an improvised tap. Then carefully use this to clean up the body thread; its best to use a bit of Vaseline on the tap to easy galling and pick up the debris.

Info given in good faith but from memory as I no longer own unit to check details. cheers John

 

[gary]

JTQ, the heater in question is 'pre June 87' and indeed used 1/2" BSP threads for the drain bung, the same thread is common to domestic water systems hence the use of standard brass stop ends.

In theory there are issues with using brass that contains Zinc in a wet aluminium casting, however given it's removed/replaced many times in a season and should be left out over winter, the issues should never build to become a problem.

Further, a little silicone grease will make sure they don't arise.

Frankly, I'd be far more concerned with the very real problems Chlorine in the water supply and aluminium cause?!

Regarding the plastic bung I've stumbled across, sadly the postman did not deliver the samples as promised this morning. I'm sure though it will do the job, better still, they won't be costing as much as the brass ones!

 

[JTQ]

JTQ, the heater in question is 'pre June 87' and indeed used 1/2" BSP threads for the drain bung, the same thread is common to domestic water systems hence the use of standard brass stop ends.

In theory there are issues with using brass that contains Zinc in a wet aluminium casting, however given it's removed/replaced many times in a season and should be left out over winter, the issues should never build to become a problem.

Further, a little silicone grease will make sure they don't arise.

Frankly, I'd be far more concerned with the very real problems Chlorine in the water supply and aluminium cause?!

Regarding the plastic bung I've stumbled across, sadly the postman did not deliver the samples as promised this morning. I'm sure though it will do the job, better still, they won't be costing as much as the brass ones!

gary: sorry to have miss lead. John

 

[gary]

Samples arrived today, looks much the same as the brass substitute but made of tough bright yellow plastic and has a 'cross' like the original for a screwdriver or coin.

Jim, if you contact me direct I'll send you one and you can give it a try

email me with your address; info@arcsystems.biz