Water jet pump extra parts.

Solid Neoprene Rubber Washer Pick Your Own Size - Size; 1mm Thick - 32mm Inside Diameter x 42mm Outside Diameter.

https://www.amazon.co.uk/gp/product/B07ZZKBSQR/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Started positioning the frames, lots of tweaking to do!

Frames and stringers.
I'm building on a lump of 3/4in - 1in ply, using the messy Gorilla glue, some parts of the board are covered with Sellotape to stop me gluing the boat to the board. the spine/Keel is laminations of various woods.

I not perfect but what is!

The old spring clamps are handy, the area forward of the solid frame, I will not tidy as will be filled with foam / polystyrene and will not be visible.

Run out of room in the shed so I am using the Utility room😆

Things were progressing OK, removed the blocks holding the frames in place, apart from Bow and Stern, cut off some excess stringers, started carving the keel, then notice the stern was not true, so had to deconstruct and also convert my clamp into a Spreader.

Regards Roy

Notes on the jet drive.
This cheap copy of a drive is excellent value but only uses a dogged propeller not a Impeller, The prop shaft inside is 4mm but its tube takes up a lot of room inside the flow area of the intake, the tube is not full of grease and the grease nipple looks more like a water cooling outlet.

I have two of these units and the prop positions were not the same so made them match,(one was 2mm further forward).
The motor alignment is not great due to the plastic support for the metal motor mount by 3 screws which is too flexible. luckily I had some flexible couplings that may help?

Regards
Roy

Beware shaft alignment, some adjustment is available via the 3 screws holding the aluminium block in position.

(note shortened shafts so I could fit flexi coupling)

Put inserts (2mm ply) it strengthens the intake area and will support the 0.7mm ply skin when applied.

Have brought two water cooling jackets but fitting will be very tight, I may have to put a flatten area on the jackets at the hull contact area.

Regards Roy

Temp removed from building board, after rebuilding stern now have had to do the same with the Bow, getting used to it now!
Add vertical to strengthened the side of the biggest compartment at the centre of craft.
Generally pleased with the frame weight.
Regards
Roy

Hi Shipmates,

More Modifications to the frame work, now it the turn of the middle section of the boat had to replace a frame as it was not right, the good thing about Gorilla glue is that is possible to dismantle a joint carefully with a craft knife cutting along the joints (I use the 18mm snap off type).

With new frame in place I am happy with the boat's side profile, then I turn back to the stern again which had been twisted across the beam (warped) away from the base board, this was fixed but I now find the stern is not 90 degrees to the hull bottom and this is essential when using jet drives.
So out comes my trustee clamp/spreader, and I break some joints and re-glue with spreader in place, once set, I add 3 right angle triangle pieces of 4mm ply as general strengthening across the jet compartment.

Regards Roy

Hi Shipmates,

I happy with the frame, now need to fit the skins.
please note there are no diagrams, pictures or plans of the underside of the hull as of yet, so I am basing the hull bottom on that of the CB90, a similar craft from Sweden which I have previously built.

Made paper templates of the underside cut them out, marked out the 0.8mm ply managed to get 2 sides and a bottom from one sheet (1ftx4ft).

Cut out the ply with some strong sharp scissors, positioned the underside and marked out the position of the jet pump intake and cut it out with a craft knife.

Gorilla glued and clamped in position to cure.
Cross fingers and hope it will be OK.🤞

Regards Roy