quinta-feira, 21 de maio de 2009

Today I glassed th first float half. It came out easier than I expected. Still there were some situations that can be improved in the future . Laying the fabric one-handed over all those form frames edges can be pretty tricky with the fabric getting stuck on some sharp corners and edges. I ended up sticking a meter long tube in the fabric roll which made the operation much smoother.
Working with the resin was no problem as I chose to make about 1/2 liter batches. Had a roller and a squegee at hand but the 6" nylon brush did the whole thing without any problem. At the end there are nearly no air bubbles and the epoxy layer looks pretty thin for a hand lay-up.
Next time I might however try to prime the foam with a thin film of epoxy to make the wetting process a bit more fluid and perhaps reduce a bit the resin uptake.
I'm short on peel ply to finnish the bulkheads but I've been doing some shopping around and I found some polyester fabric that might do the trick. Polyester is better than the nylon used in commercial peel ply but it's not as tear proof as nylon and special care must be observed to avoid the polyester fibres getting stuck bonded in the laminate. To avoid this plies should be cut long enough so that there's a sufficiently large resin free fabric overlap to get a good and even grip.

quinta-feira, 14 de maio de 2009

Chainplate pads

This doesn't seem to be too difficult to make but still it helps if you find a simple, fast and effective way to get there.
This is how I did it.

First I traced the curvature on the foam blank using a strip of foam.
Then I cut some slits with a metal hand saw as a guide for the amount of foam that had to be planned off.
Finnaly used a small hand planner to cut the foam to the desired shape. For better results the planner should be driven into the foam at a 45º angle.

Simple does it!

First float half is almost ready for glassing. It took me some time to figure out how to make the 20x20 foam fillet until I realized I could make them off the fillet cut-offs from the stringers. Each 2.5 meter stringer blank gives off 5 meters of fillet for it only takes an extra meter to complete the float lenght.

Vacuum test

Before I get serious about vacuum bagging I did a test run using the aft beam bulkhead. I didn't give it much thought and actually let every possible mistake to take place. This way I hoped to avoid making fatal mistakes later on.

This test gave me a lot of information regarding the whole process. I have all the parts ready for vacuum but I don't have enough peel ply to do the whole operation so I'll wait for the material .

Chainplate pads

For the past week the work on the project took all kinds of forms. Besides some shopping and cleaning up I made a custom cart to carrie around most frequently needed tools and acessories including ilumination.
Down at the bottom you can see the vacuum pump unit. The idea is to build different modules that can be hang up on the cart depending on the operation ( vacuum baging, foam planking, gluing, glassing,sanding,etc). This way everything is at hand and there's no need to wonder around the shop looking for stuff. The cart can also carry special jigs such as a hands free support for the heating gun to preheat the foam. I hope I can save some precious time with this thing.

domingo, 3 de maio de 2009

The Boat

For those of you who don't know what an F-22 looks like here is a picture of Sam Ballard's F-22 built in Maine USA.
Although there may be differences between one boat to the other mine will hopefully look something like this.
From now to then there about 2000 hrs of work!
With ups and downs , fun and some pain I will get there!


Today the temperatures got well into the high twenties so it was an excellent opportunity to put the fast epoxy to work by bonding the scarfed battens. It was a pretty tedious operations having to make 130 ml batches and try to make 3 battens at a time. In order to use a single pair of clamping jigs I stapple gunned the joints and carefully moved them over to free the clamping jigs for the next batten bonding operation. I was afraid the joints might move and ruin the whole job but everything worked out just fine.
It's amazing the way the learning curve evolves along the process. The first batten must have taken me about 45 minutes to set up and bond, while at the end I could easely do three battens in about 30 minutes.
In fact the first bonding operation had to be done over because of a wrong resin/hardener ratio. The thing wouldn't simply cure! It turned out that the stapples where a bit off mid section of the scarf so it was a good opportunity to fix up this problem too.

This was the first contact with the resin and it was a good opportunity to calibrate the batches for maximum resin rentability.
I was afraid it could become a bit messy but it all come out nice and clean. In fact never had to put the nitril gloves on.
At the end used some left over resin to seal the boundaries of the mdf form frames. I noticed that some srews were sweling up the borders.

I will be planning in advance some side operations where I can always use excess resin and or glass. Maybe I'll make some custom tools to use later on in the lamination process.

sexta-feira, 1 de maio de 2009

Foam workbench

Today I spent the morning cleaning and moving stuff around to make space for the project.
In the afternoon I used some steel profiles I had around to make a workbench for the foam to store and cut the foam sheets.
I'm still considering making a cheap aluminum linear guide where I can mount a rasor to make cuts easier and more precise.

Here you can see the the foam box already in its place. As you can see it's a pretty large box hard to stock away. This way I can put a laminated sheet on the top where I can cut foam on one side and eventually do some other operation on the other side like vacuum bagging.

I'm amazed how well this structure came out. I'm not an expert welder and I usually end up with a leg setting way out of level but this time it came out perfect!

My daughter "helped" me put the box inside the structure. Kids are always so strong , aren't they?

One down ! More to go !