Wednesday, 24 March 2010

I have been thinking ahead about ballast.  Thinking that ready-mix concrete might be the answer I started a thread about concrete as ballast on CWF and the resulting discussion I think I might have found the perfect ballast material.  Seems concrete might not be a good idea.  I say might as there seems to be no clear feeling about it accept in France boats built after 1997 are not permitted to use it. DBA article

So then I thought Granite. I rang my brother (he owns a stone workshop) and asked what he did with his scrap, i.e. the bits he cuts out for cookers, sinks and other wastage. He puts it in the skip he told me, about 3 tons a month!  30mm thick is 90kg sq/m its non porous, its lose and for me best of all its free.


These are typical off-cuts and I can use it in 3 layers if need be. Each one of my bays is .8sq/m so I could get over 200kg in each.

Sunday, 21 March 2010

Back To Inside Welding

Took the welder back inside again to do some more welding. Remember the slots I made a while back in the top of the sides?  This is why.



The middle weld is the the reason.  This weld joins the back of the D section on the outside to the top of the side panel and provides a hidden weld to make the bottom of the of the D section stable.  The other 2 welds are long tacks just to add more strength to the roof to side panels.

 Here from the outside as a reminder


Saturday, 20 March 2010

Non Visual Stuff

I have been busy this week doing background stuff.

I have been discussing engines, cooling , gearboxes, drive gear, bow thrusters, with a very helpful chap.  I had originally wondered why my shell had been built with a mud box instead of keel cooling.  On deciding on the engine power (I want around 90hp) it was clear after running a calculator that I could not put efficient skin tanks in.  90hp needs 22.5 sq/ft of contact area.  Realisticly this is going to be a non starter.  So it looks like the mud box or raw water cooling via a heat exchanger is going to be the answer which is why it has a mud box.

I have also ordered the windows.  8 off 36"w x 24"h Dutch barge style windows and 3 off 18" port hole windows.

Building a boat is more than just tools and graft.  There is a shed load of research too, especially if it's your first one.

I have also bought an inverter.  Probably a bit premature but it was a good price so it can go into store for now.

Tuesday, 16 March 2010

I Have A Dry Boat

It kinda feels like a right of passage of some sort, but I have a dry boat.  The small bilge pump got most of the water out, but it got to the point that the individual bays wouldn't drain anymore.

I got the George out of the house much to my wifes displeasure and set about sucking up the water and the decaying leaves.

Note:- Blogger has distorted this photo.  Double click to see it correctly
In this it looks like a NB :-(  LOL.

Another construction milestone is the removal of all the internal bracing.  Its amazing how much bigger it looks with these removed.

Sunday, 14 March 2010

Nearly Have A Dry Bilge

I have now pumped out as much as as I could with a bilge pump.   The rest has to be sucked out with a wet vac.  The brown stuff is mostly decomposing leaves which are easy to remove once the the water has been sucked away.  Don't smell too nice though.

The bin is about a third full of wet leaf mulch

Only 18 more bays to do

Friday, 12 March 2010

Number Crunching (I'm a bit of a saddo)

Because I like strange things like numbers I decided to find out how much MIG wire I have used so far.



I weighed 1m of .8 wire at 4g  which means on a 15kg roll there is 3750m (3.75km) of wire.  I have used 3 of them so far so I have put 11.250km of weld wire or very nearly 7 miles!!

I'll get my coat :-)

Thursday, 11 March 2010

Welding In More Detail

Today I finished the port side welding (side to gunwale).

I thought I'd show in more detail the welding process from applying the weld to the final dressing.  Its not a difficult job but it is labourious.  12.4m again this time took 1 session and 6 hours 4 x 115mm grinding disks and 8 x 115 flap wheels.  

Stage 1. apply a good deep penetrating weld fillet

Stage 2. grind back to concave with a grinding disk

 Stage 3. polish with the flap wheel

 Stage 4. beacause I am welding outside the wind occasionally
blows away the weld gas which is the flux
This causes small holes which need filling with more weld

 Stage 5. back to stage 3

The final finish will be with a DA prior to painting.

Wednesday, 10 March 2010

Flap Wheels Are A Miracle

 What a brilliant invention

I now have all the roof welded shut along the sides.  I still need to finish the cross wise welds.  My welding umbilical is too short so I am going to have to put the welder on a trailer to gain some length to reach what I have been able to do.
I have now welded the starboard side bottom to the gunwale and dressed the welds ready for paint.  

Smooth


The flap wheels have made this job so much simpler.  To weld the 12.4m and dress it has taken about 6 hours.  The bulk off this was the dressing.

I did use flap wheels on the roof dressing as well, but they really have come into their own on this job.

BTW it has been Bl**dy freezing today.  The wind has been from the N.E. which for us is the worst.  I was chilled to the bone.

Friday, 5 March 2010

Thursday, 4 March 2010

Plenty of Welding

I am currently welding the roof to the sides and adding a D section to the top of the cabin side.

The weld length is 12.4m each side and the average gap to be filled is 5mm wide 4mm deep and 3 sections of metal need bringing together and finished flush with the curve of the roof.

From left to right there is the D section,
at the bottom of the gap is the top of the side panel,
then the roof.  Tacked in place.

To get good penetration and fill this gap is very slow going but in 3 days (not solid) I have completed the port side.

First, loads of weld blatted in

 Next, grinding back and finishing

Griding back is a 3 stage process.  First it gets a heavy grind with a 9" grinder, heavy but careful as its easy to over grind and end up with an undercut which would need filling with weld again.  Next stage is polishing with a flap wheel, followed by the third stage which is linishing with a belt sander.

I said at the beginning it was slow going.  Each 1.5m roof section is taking about an hour and a half.

I will not be welding the underside.  This will be finished with a special polyurethane sealant.  So to ensure the D section has another attachment I have plasma cut some spaces in the side so it can be welded from inside.  I will show this when it happens which will be when I weld the inside roof / side joint.  Below are the spaces cut.
Slots every 500mm

 The starboard side is next.