Transferred from Chit-Chat
https://www.modelboatmayhem.co.uk/forum/index.php/topic,62612.0.htmlObservations:
She’s bow heavy. Water level about 4mm above the waterline at the bow and 6mm below at the stern.
Has a very very small seepage where the starboard prop tube goes through the hull.
Prop shaft inboard tube ends are 25mm below the waterline. Sings of water getting up there. How do you keep the water from traveling up the tubes? Starboard seems worse that port. See photo.
Rudder spindles are also below water line but seem to be leaking.
Electrics are a mess – no fuse protection at all. No switch on the battery cable. Components not secured properly.
From malcolmfrary..............
Bow heavy - the main contributor to the center of gravity is the battery - a lighter battery plus compensating ballast will allow this to be corrected by you being able to pick where the battery and ballast go.Seepages around prop and rudder tubes - application of epoxy to seal the gaps. Thinned slow epoxy to get into the probably very narrow gaps.
Water resistant grease is good for stopping water from getting up prop and rudder tubes - also good for lube. Look through the site search engine, there are as many preferred tube lube solutions as modellers.
I didn't see any in the pics, but I would look for some brass or stainless washers to use as thrust washers at both the inside and outside ends of the shaft. They also serve as seals when greased.
Other white metals apart from aluminium are steel and nickel silver, you find out which when the surface corrodes.
As an ex-electric tech, I have found that modern electrics in sedate models don't need much fixing down, just enough restraint to discourage them from wandering around. A bit of plastic channel from the useful bit at B&Q does that. The rubber band shown along with the natural stiffness of the wire will do a perfectly adequate job. Sometimes Blu-Tak does the job. Depends on whether or not anybody will be looking.
I am assuming two motors but one ESC. A fuse between Battery and ESC is usually surplus - it is only protecting against a faulty ESC. Fusing the individual motors is a good idea when there is more than one motor as it provides a handy test point..........................
Malcolm - Taking a closer look at where the SLA is placed I can now see that there are two pieces of plastic angle that are fixed 135mm apart (shown below) that is the length of a 6 cell rechargeable so I think its safe to say this boat has had a 7.2v battery in it before. As you and another have suggested to go that way that is what I will do. There is a weight difference of approx 320g, the Ni-MH being lighter. This alone may cure the COG problem but it may also make the boat sit a bit higher in the water. Would it be correct to say the closer the boat sits to the waterline the more stable it would be? Either way extra well placed ballast would sort it - yes?
Seepage is easily cured with filler as you suggest - I wont have any problems there.
Panic took over with the 'water up the stern tube' thing. Your advice and what Ive since gleaned from the internet has made me realise its no great deal if approached correctly. Various washers (nylon, neoprene and brass) have been ordered plus some prop grease.
You assumed correctly - two motors one SLC.
I have now decided to strip out the electrics, props and rudders to check everything and change if required.