Tuesday, 14 May 2013

Good and not so good!

It’s mostly rained today and we accordingly came to an early decision not to move.  We have no timetable to meet so we can afford to wait until things improve.  One might almost feel sorry for the boaters passing us in the rain, except the majority don’t reduce their speed to ‘tick-over’!  Jan suggested we consider passing boats at the same speed but two wrongs don’t make it right!  I put out a ‘spring line at the stern which has had an effect but it’s too shallow to get Waiouru against the bank and consequentially we end up with list.  

The Hurricane is continuing to perform faultlessly and we’re optimistic hoping it will continue.  My assumption is the last problem was caused by my overfilling the diesel tank thereby preventing air bleeding out of the fuel.

In between showers I went down the weed hatch to complete a temporary modification.  What I find good about the design of the weed hatch is it’s separate from the engine bay with access obtained from the stern deck.  If it was in the engine bay then there is a potential risk that the hatch cover could loosen and water enter flooding the engine compartment with the further possibility it might result in the boat sinking.  Having a separate weed hatch eliminates this risk.

If the handle is turned anti-clockwise it loosens the screw thread and allows the white bar to also turn anti-clockwise from under the black locking plates.  When the ends of the white bar are clear the handle, bar and hatch cover can be removed from inside the weed hatch.  This provides access to the drive shaft and propeller.  It’s a good concept!

The not so good part of the design is the bar can actually work loose allowing the canal water to surge up into the weed hatch chamber.  There is no danger of this sinking the boat but it makes a hell of a noise.  In my opinion the design isn’t quite right.  Instead of the white bar being secured under a piece of angle iron at each end it should be a piece of inverted ‘U’ channel.  That way the bar would not be able to twist out from under the end catches.  I’ve devised a temporary solution.

The 3” G clamp prevents the locking bar from turning.  This is actually the third clamp we’ve purchased.  The previous two were purchased from the 99p shop and snapped under the strain.  This is only temporary and the permanent solution is to modify the angle iron to ‘U’ channel.  It’s not a major job.

I’d be interested to know if this is the standard weed hatch design for a Wilson-Tyler shell?  Actually there is one more issue!  The hatch baseplate doesn’t fit flush over the hole in the uxter plate.  As a consequence we get canal water surging around the bottom of the weed hatch compartment when the propeller is turning.  We might try to minimise this by fitting a heavy duty rubber/foam strip around the edge of the hatch baseplate in an attempt to seal it.

Looking at the weather forecast for tomorrow, it’s more showers.  Somehow I think we’ll be staying where we are!


Adam said...

Yes, this is the usual Tyler Wilson weed hatch design -- most other builders have it open to the engine bay.

I've never found the bar working loose, though. What I do is use a lump hammer to tighten the screw, and I always need to use the hammer again in to loosen it. The problem with a U channel would be that the screw would need an awful lot of turning each time, which I'd get bored of quite quickly.

David said...

Hi Tom

A 'U' section may make it difficult to rotate the locking bar. How about drilling through both bars where you have the clamp and just drop a bolt through. No need to secure it as its weight will hold it in place.


Halfie said...

Tom, for some reason the first photo doesn't appear, so I can't see the whole picture. Looking at the second photo, if I've got it right, your current setup is that the angle iron is effectively holding down the white bar which is pushing the weed hatch cover down into its sealing position. And I deduce that the angle iron the other side has its open side facing the other way. If you have an inverted U section each end of the clamping bar, won't that prevent you sliding the bar into place?

Alf said...

Does the plate not have a foam seal at the moment ? most weed hatches do, so do fit a seal, the foam can be obtained from most chandlers with a sticky side to attach it to the plate.

Tom and Jan said...

Thanks for confirming it's a standard design. I was planning to make the missing side of the proposed 'U' channel much shorter to reduce the number of turns on the screw.

The bolts are a good idea (actually I already thought of that. However I'm not sure they wouldn't 'bounce' out of the hole when underway. But the idea hasn't been discarded.

The bar can be raised and lowered by turning the handle. Not sure why you can't see both photos. I've checked twice and they are both there?

No foam seal at the moment. That's what I'm thinking of installing.

Halfie said...

Aha! The top photo has appeared now. It was either my computer or Blogger. (But clicking on it takes me to Picasa "page not found".) I think I see how the inverted Us will work now, especially with Adam's comment about having to turn the handle a lot. How about merely dropping a piece of wood in to wedge one end of the bar against the angle iron? Try it with a log!

Adam said...

On the sealing issue, surely the whole point of this design of weedhatch is that it doesn't need to seal. A normal one does, or you fill your engine bay with water; this design means you can't do that. And I doubt whether you'd ever manage to get it water free anyway. The plate sits below the water level and the hatch is funnel shaped, so you're unlikely to be able to push the water down. And if yours is anything like our, the bilge pump empties into there too.

Tom and Jan said...

Hi Adam,
Yes, I appreciate the weed hatch compartment will always have water in it. However I'm concerned about the size of the gap and there are already signs of build-up of mud, etc in the base because of this. The bilge pump doesn't empty into it but the hose from the water lubricated dripless seal on the drive shaft does.

Don Mc said...

Another way of securing the hatch is to fit a piece of timber between the white bar and the side wall of the weedhatch well. If this is a taper fit it will wedge in securely as there is moisture which will keep the wood a firm fit. A short piece of light rope can be attached to remove the block.
I think,however, that the bolt / pin option is the simplest and this will not rattle out if it is long enough.

Jannock said...

When you decide to replace the weedhatch seal use a closed cell foam camping mattress. Usually about 10mm thich and works a treat. Can be bought very cheaply from Aldidl (They both seem to stock the same stuff)

Tom and Jan said...

The idea if cutting a rectangular section from a cheap camping mattress looks to be a better solution than purchasing foam tape from a chandlers.