Centreboard number 2

Second centreboard was infused over the weekend. This was the best vacuum infusion that we have done. We took all day Saturday to set up. Five layers of glass and an extra strip along the leading edge, if these boards break, tears will be shed. Peel ply was sown to the bottom of the board so that it does not creep up during the infusion process. Next came the release film followed by the breather cloth which was set up in a grid to lead the resin over the board, this was again sown to hold its position, we tried to staple but the staples were not cooperating. Last of all the vacuum bag over the top.

Sunday morning we pulled a vacuum anticipating the normal leaks. This time the gods were smiling on us as we only had a few small leaks which took a few minutes to seal.

We set up 3 ice cream containers ready for the quick initial uptake. All preparation completed, we were ready to go.

Approx 10.00am with the temperature around 25 and humidity around 34% (perfect conditions) we started the infusion. It is good to watch your hard work come to fruition. Watching the board wet out is very gratifying. We kept mixing and infusing resin as needed for the next 1.5 hours, but of course not everything can go perfectly, the leading edge was dry. You could hear the brains ticking over, how are we going to fix this problem. Then the light went on, just like a cartoon scene, we changed the top (leading edge) vacuum hose to a resin hose. It worked like a charm, within 15minutes the leading edge had wetted through.

Unwrapping the board the next morning was proof that the process had gone well. No dry spots. Next is the sanding and final shaping

Shaped centreboard blank before glassing

Breather cloth set up

Set up with hanging tubes

Calculation of resin used

Infused centreboard you can see the spine and foam strips through the wet glass

2nd time lucky

We were always going to vacuum bag the centreboards just didn't expect it to be such a large learning curve. We thought that we had made all the required bloopers that are part and parcel of learning when we vacuum bagged the two centreboard spines. Duh, got that one wrong, still more bloopers to etch the experience on the brain.

Wrapped up the centreboard with all the required glass, plus extra for our own peace of mind, peel ply release film and this time we used shade cloth for the breather fabric. The decision to use of the shade cloth was made after discussions with some local builders who had used it and having seen others on the web using with no difficulty. Great option in that it is a lot cheaper and more readily available then the specialist cloth.

Everything was tested that night to make sure that there were no holes in the bag. All set for an early start in the morning.

Early morning and everything seemed so smooth. Temperature under 30, humidity low. Everything going swimmingly.

Pulled the vacuum, mixed the resin unclamped the resin line and whoosh, within a flash the resin was sucked into the bag. More resin mixed and whoosh again. We were going great guns.

Ian had calculated how much resin we would need based on the amount of cloth around the board, yep we soon passed that calculation. Ok that means that the cloth and hoses should now be full. The resin intake was slowing as the resin was spreading across the board, everything was wetting our beautifully. Eventually the resin stopped being sucked into the bag, sorry can't remember how long this took. From the outside the whole process looked perfect. Ran the vacuum till the resin went off and then went home.

Next morning we went to work early to take off the bag before the guys rocked up. What a disappointment. Fully infused shade cloth and top layers of glass, but had not gone through to the bottom layers of glass. Nothing could be done to salvage the situation. Everything had to be taken off the board and binned, and the board sanded back to shape. What a waste of time and money, and very very demoralising.

But we did learn. Next time we went back to the specialist breather cloth and ran it in a grid to direct the resin to where it was required.

What a difference. Resin went in at a slower rate, you could see through the bag where the board was being wetted through to the foam. Any dry spots we injected resin using an idea from Westsail 42, used a basketball needle inserted inside a syringe. We were confident that this time all was going to go well.

Next day, opened the bag and this time no heart ache. This time it all did look perfect. Ian had to cut a diagonal piece off the top of the board to give it the correct shape. This is great in that you can see how deep the resin has penetrated. Just as we thought, through to the foam and glass on the spine. Very very happy.

We, well I should say Ian, have now shaped that board and it is in the final stages of bogging, sanding and sealing. With the extra glass on this board I am confident the we have a very strong board.

Pictures will be attached soon.

Rudder work to follow soon.

little helpers

The smallest things are so handy.  You look at them and wonder maybe I could use that.

We have been known to be reticent about throwing things out and that creates a bit of a jumbled mess but also saves you money when creating.  We have saved most of our offcuts and have bits and pieces of foam and wood of various sizes and shapes.  Amazing where you find a use for them.

Fellow builders suggested, and kindly gave us some little tile wedges/spacers, we have found numerous little places where they come in handy and they don't stick to resin.

4 letter word beginning with w

Yep thats work.  Paid work that takes your time away from boat  building.

We are fortunate that we are steady at work in the curent economic climate but that also means that the boat work only happens for a few hours at the end of the day and on weekends.  Makes it frustrating in that the boat work is slow but we are fortunate to be receiving an income to assist us in buying the bits and pieces that we need for the boat build.  All this means that we may have to wait a little longer for the launch.  So be it.

Boat work has still been progressing and we now have a few projects on the go.

Still shaping the centreboards have also started on the seagull striker and rudders.

The shaping jig is working a treat and has proven to be very good at showing when things are a bit out of kilter.  We were sure that the foam strips were glued straight with no little whoopsies in them, that was before we started routing the board.  The bottom of the board was showing little cuts whilst the top of the board was taking off larger chunks of foam.  Solution was either to cut and re-glue new bits of foam or use more bog.  Cut and re-glue new bits of foam won.  The boards are now straight with no warping.  that makes me very happy.  They should move smoothly up and down the centreboard case.

Centreboard prior to routing

Leading edge routed

Centreboard shaping jig

Ian has designed and built our centreboard shaping jig.  Should have been easy, the design was relatively simple however when things are not triple checked time is wasted.  The little things that went wrong are:

1. The wheels to run up and down the rails were to have a 1/2" hole drilled in the centre.  They came back with 12mm holes and not centered.  Fortunately this was Wednesday afternoon so we took them back to be redone.  Low and behold the new centres were correct but still 12mm.  Fixed late on Thursday afternoon (before Easter) by our friend who runs the machine shop.
   
2. Ian picked up 10 x 50mm steel for the  rails, ran the now completed wheels over it on Thursday afternoon and could not work out why there was slop.  Immediately blamed the machinist but this time his measurement was spot on, then measured the steel it was 2 x 3/8.  Too late to do anything, everything is closed over Easter.
   

It truly makes me wonder about Australia being a metric country.

Started the basic shaping with the slightly wobbly jig.  Works very well, we will do a rough shape and finish after Easter with new wheels to stop the wobble.

How it works

A template is fixed to one end of the board, the router is adjusted left/right, up/down to the correct position then the jig is run up and down the rails.  So as not to erode the template a tally-ho tobacco paper is placed on top and adjustment is made till this paper is touched.  Sounds simple if you say it fast.

Setting up the jig

Test run

gob smacked

That is how I felt when I read comments on my blog.

I find it amazing that anybody besides my family would be interested in reading about our boat building progress.

Thank you for the positive comments posted.

One comment asked which resin we used for the vacuum infusion.

Here we are very fortunate to have made friends with another couple who are well advanced in building their Schionning Wilderness.  Their build quality is excellent and they are very kind and impart little tips to us every time we meet.  One excellent piece of advice was to use Kinetix R246TX resin with H160 slow hardener for our vacuum infusion.  The working time is hours compared to minutes.

Ian is working on the centreboard jig.  Pictures soon.

Oh so big

We have cut and glued all the foam strips to each other and to the front and back of the centreboard spine.  A lot of time being spent with the set up to make sure that everything is straight.  The foam by itself was very flimsy.  With the gluing complete you can see the shape and stiffness starting to happen.

When standing the boards are humungous but taking into consideration the height of the hull the depth in the water is not dissimilar to many racing dinghies.

Next stage is to make a jig up to shape the boards.

One of the centreboards just finished gluing.

A picture to show the height of the boards