Hello, because I am new to rc boating, i need some help with figuring out how to seal a flex shaft/stuffing tube. First of all, how does it work? Does the flex shaft pass through the stuffing tube which seals between the hull and flex shaft? What do you put in the stuffing tube to seal it? Thanks for the help.

What type of boat ... V - Cat ??

post some pictures of the boat and the inside is best

First there is no sealing.A stuffing tube is a brass pipe. Some not all have a teflon liner .I don't use one.My brass pipe is heated to anneal the brass. make it bend-able. some hulls have a bent stuffing tube usually bent in a s-bend .Yes there are straight shafts.We are talking flex-cable with a threaded shaft end. I epoxy /resin in a brass s-bend pipe into my new hull. the back end of the tube will go into my strutt.You can call that sealed I juess. the inside pipe is inline with my engins flex coupler. Some builders have a L-shaped brass pipe as a stuffing tube.A larger dia pipe than the L-bend is epoxed in the hull. then you can pull the L-shaped pipe out of the hull.It's locked inside your strutt say 1/4 ". The inside of the pipe/stuffing tube. the one ending before your flex coupler. 3/4" away that ends.you may want to add a shaft saver. somthing to hold your flexcable if your flex coupler loosens. A teflon pipe is used to slide inside.I don't use that. My cable shaft is always well greased.When I slide it inside my strutt. Put a flexshaft inside a drill and the shaft inside the strutt turn on the drill. What do you see. do the same with your brass pipe. a long sloping "S" Mount your engine as low as you can angled . Where do you mount your engine @29-33% of the hole length of your hull. from the transome. your flex coupler is used as the engine mark not the plug. Or set your coupler at 33% of the hull or 1/3 of the hull you didn't say what kind of hull you have I'm thinking mono. Hydros are different riggers are different still setup wise.

bshey wrote:
Hi Bshey

I run mono deep V boats. The stuffing tube as said by Neil is a brass pipe (tube).
It contains the flexi shaft that delivers the turning force to the propeller.

In terms of preventing water getting into the boat, the grease or chosen lubricant within the tube will prevent water getting into the boat via the internal gap between the tube and the flexi shaft.

In respect of a mono hull the tube exits the transom at the lower part of the V. At this point it will need sealing to prevent water ingress should the boat stop. One can use a flexible silicone sealant (to enable future strut height adjustment) or fibreglass paste if the set up is to be permanent.

These two photos show my stuffing tube after installation. It is supported at three points. At this stage the exit through the transom was not yet sealed although the tube is still supported outside the transom by way of the strut support in which it slides into.

For me the most critical part of the installation was to ensure that the tube was accurately in line with the engine drive shaft to minimise friction and vibration.

Cheers
Craig

Yes I see what you have. your OK you need a stinger drive. As far as sealing the back you stinger drive will seal all water.All adjustments are done via your strut.You will have plenty of room to make adjustments.If you do need to seal more Resin or GOOP .looks like you also have a auto-bailer in the transom. Down the road you wish you never used one.I just pour the little bit of water out.Auto-bailers are really not needed. You will need to replace them annually or semi annually.My Easy Vee gets 1/2 cup of water during a heat race. All-open www.kintecracing.com/Hardware.html

Yes I do have an auto bailer at the transom. I find that provided it is cleaned after each run it does deliver results draining the water out when running and keeping it out should the boat stop.

These two pics show the transom end of my boat finished prior to the decals being added:

This clip shows the boat in action:

Yes I see a auto auto-bailer is best. Your hull top keeps tipping it over kinda hard to get any water out. My new AC lighting Cat.21 I may wait until I run her then decide on the the bailer. The top is built so I could pour any water out. The some of the new gas cat hulls have that cantilever transom. That header is preventing the full potential of your tuning pipe. 14 1/2" and under down to 11 3/4" length. A 100degree or 110 degree header pipe is very common. Very nice job. that's a great hull. nice run

Thanks Neil. I am thinking about changing header to a 105 degree to get the pipe length shorter. The only small issue is that it would need quite a lot of the top cutting away which would spoil the looks.

Anyway I guess that's straying off topic.

Craig