Wednesday, September 26, 2012

Shaft R&D

We were attempting to reinvent the wheel.  Then my wife told me about youtube!
Bringing shaft manufacturing in house is a big goal for us because of the savings we could realize. Actually there are many more reasons.  The fact that we would not have to wait on delivery of ordered shafts and the ability to go with specific colors are two big ones.
So I was trying various methods I thought up to spin shafts of glass on a mandrel.  The removal of the tube is the problem to be overcome.  I tried two things.  One was pva on the mandril and air pressure to remove the part.  The other involved wax!  Crazy.
Christabelle found this guy:
http://www.youtube.com/watch?v=q3wtcNTd9wg
It appears he is making tubes for model rocketry.  Very cool.
We applied his method yesterday and immediately produced a great sample with three different glass schedules.
We had no mylar on hand and to keep cost down we were going to need to find a less expensive substitute.  Tyvek came to mind as it has several similar qualities: Resin doesn't stick to it and it has dimensional stability. (Does not stretch).

To get even wrappings with speed and efficiency we are going to engineer a geared mandril.
That is the next step.
But the hand laid tube looks good and is very strong.


Tuesday, September 25, 2012

SUP deck structure

The Sea State SUP is designed to be sold as a kit.  Finished boards will also be for sale.
The board is made up of 4 panel components.  The largest part is the hull bottom.  It is a structural skin molding of biaxial glass.  This part is the full length of the board and includes the side rails.
The deck structure is composed of the foredeck.  It is also a biaxial glass molded part.
The aft deck is of the same structure and size.
The kit part of this sup is the rest of the deck area.  A selection of wood strips, glass cloth and epoxy are included so you can get creative with the look of this SUP.

When purchased as a kit, the fore and aft decks are already glassed onto the hull.  Stringers are installed.  The only work required is the design and installation of the wood strip deck.

Below are photos of the foredeck structure being formed.  Once this is completed, this part will be molded.




Sunday, September 23, 2012

SUP mold

On Friday we had the plug polished and ready, so we sprayed on PVA and prepared to make the mold.  To have everything organized is essential with such a big part.  We precut the variety of cloths used for the mold.  We made sure all the supplies were at hand including a fresh bucket of Vinyl Ester, latex gloves, several respirators etc.
We sprayed on a tooling gel coat Friday night and on Saturday morning we started a wet layup of the mold.  We ended using about 3 gallons of resin.
On Sunday after lunch we were able to easily free the mold and quickly declared victory.  The mold is nice and clean.  There are a couple of voids we will fill and polish in the morning.
On Tuesday we plan on forming our first part from this mold.

This photo (added Oct 7th) is of the first part pulled from the mold:



The mold just after it was popped off the plug.  Wooden shims and plastic wedges are used to prevent scratches.
The mold has some stringers embedded to add strength.  This mold should be able to produce  many parts.

The mold before washing off the pva skin.


Monday, September 17, 2012

Skiff at Polestar Marina show

We had the skiff out this past weekend at  Polestar Marina.  There was a car and boat show.
Here is  a photo of it with it's new gunnel.
We sold the Johnson 25 because it was just too large an engine for this hull.  The power was no problem but the weight made the stern sit too low in the water.
The ideal size would be a 5 to 15 horse power.
We are looking for an older Evinrude of Johnson.  The older styles look better on this boat than a newer motor.  Of course a brand new Mercury would look pretty good too.


Friday, September 14, 2012

Paddle Board the next step

Yesterday evening we sprayed on a second layer of gelcoat.  The fairing process is getting very close.  With this last coat we changed colors.  When sanding it allows you to see when you are through the top coat.  We have a couple of spots we are going to fair out then she will be ready to polish.



Tuesday, September 11, 2012

Paddle Board plug fairing

Today we spent some time fairing the plug for the paddle board.  It was first formed with 1/8 inch ply. bi-axiel glass cloth and resin.  We then formed the rails with fairing compound and lots of it.
Once it got close, we gel-coated it.  Getting the plug back to a uniform color with gelcoat helps in the fairing department.  It is easier to see problems.  So today we re-faired and tomorrow it will get another gelcoat layer.  At that point we should be getting real close to polishing time.



Monday, September 10, 2012

Carbon Fiber molding

We have worked out all the kinks in the carbon fiber molding of our Cahokia blades.
The blades are made with a 6.2 oz large checkerboard weave carbon cloth.
Initially we where having bubbles in the finished surface that required either rejecting the part or costly finish re-work time.  Our improvement came when we modified our vacuum form to pull the bagging film from above the part with no breather material.
It progressively clings to the part and does not trap air.

The parts spend little time in the vac because we still have Missouri summer weather.  We pop them free and set them in the sun to finish curing.  We will shortly get on the shaft mandril form.  That will be fun to figure out.

Stay tuned...