Monday, November 26, 2007

Laminate quality part 2

Well I guess practice does make you better. I removed the peel ply tonight on section 2 for inspection and it is even better than the first section. The white peel ply and the plastic sheet really allow you to 'have at' all the problem areas. It is a combination of visibility and the freedom to work the whetted cloth without damaging it.

In terms of cloth to resin ratio I can report the following

  1. Each layer of the 8.9 oz/sq yd cut to an area of 50" x 35" weighs about 12 oz. So with the two layers I am applying there is ~ 24 oz of cloth involved.
  2. I mixed up about 29-30 oz of resin and there was a little left over, that I did not weigh. I am assuming I applied about 27-28 oz of resin onto the surface of the float foam and the cloth. I also suspect that with this wet technique there is alot of foam surface roughness that has to be filled up to get good adhesion.
  3. I weighed the peel ply after removing it tonight and compared it to a similar unused sheet of the white peel ply. Unused the 3 oz peel ply weighs 4.95 oz. After peeling it with the epoxy saturating the material it weighed 7.25 oz. So there is about 2.25 oz of epoxy in the peel ply.
I can conclude that I am approaching a 1:1 resin to cloth ratio. Perhaps with vacuum bagging you can do better, but after looking at this latest result I am very very happy with what I am achieving.

It is really a huge thing for me. I was very concerned about my ability to produce a high quality outer hull laminate.

Sunday, November 25, 2007

Laminate quality

I'm posting a couple of pictures that show the surface features of the laminate. It is not easy to get the camera to focus at this distance. I'm interested in getting some comments on the quality of laminate that I am producing and the 'dry' or 'air bubble' features that I am seeing.

Above is a good area.

Do I need to repair an area like this? The glass is hard, well adhered to the foam and there is no obvious bubble dome. Comments?

Here is the next section with peel ply and plastic on the glass.
I've purchased some white peel ply and I have to admit I like it a lot better than than the black. Visibility as the peel ply goes transparent is obviously much better. I'm just doing one more 50" length section on the hull until I have a better handle on the technique.

Thursday, November 22, 2007

Carbon fiber mast poll

I've removed the poll as it was clear that there is definite interest in a group purchase of the 35' F22R carbon fiber mast. Ian Farrier has also made a comment on Nov. 10th in the yahoo F-boat forum regarding a group purchase of F22-R masts and a special Al extrusion specifically for the F22.

"If you don't need your F-22 mast immediately then I would advise holding off for a while. I will be getting to mast options soon, and with so many boats in the pipeline it may be possible to do a bulk buy on F-22R carbon masts for the benefit of all builders.

I will also be looking at designing and extruding a specific aluminum mast for the F-22, one that has the optimum properties and least amount of weight for that purpose. The numbers could be such that a container load of masts can then be shipped to major population areas keeping prices to a minimum.

I used to arrange mast group buys in Brisbane for the Trailertri series, and at that time was able to supply mast sections for around $150 each. Will not get even close to that now, but I think it will be possible to do a lot better than builders buying individually."
I for one will wait and see what he will come up with.

Sunday, November 18, 2007

Starting float outside laminations

It is time to start the propane heater if I am going to do any laminating in November.

The float has been sanded, filled,sanded, much as I can. It is as prepared as I can make it.

I have decided to follow the following strategy for laminating the float exteriors.

  1. Lay the first layer of the 8.9 oz 7781 cloth down. The bolt is 50 inches wide so I will be running a number of widths down the length of the hull. This allows the finished edges to run vertically up the hull.
  2. I require to lay two layers of the cloth to make the specification of 16-18oz fiberglass weight. This gives me an opportunity to offset each layer 3" down the length of the hull and have only two layers of cloth everywhere. No need for rebates to compensate for extra layers of fiberglass.

Getting the two layers of cloth wetted out and lying smooth is always the hardest work. Here I have just laid out the second layer of style 7781 e-glass cloth.

After smoothing out the plastic on the peel ply I used masking tape to hold the edges of the plastic over the gunwale, keel and bow tight curves.

The temperature is about zero outside but on the plastic it looks like it is almost 15 degrees celcius. Warm enough for epoxy to cure.

Seven hours later the resin has cured sufficiently to relese the plastic. It just lifts off , no pulling or peeling, leaving a very smooth glossy peel ply and laminate. This technique certainly saturates the peel ply with excess resin.
I'll update when the peel ply comes off. I had planned to go farther down the hull in this work session. But as the fates have it I ran out of peel ply. So, if it looks as good with the peel ply off I'll be full speed ahead when I get more supplies.

Pictures with the peel ply off. Superb adhesion with no air bubbles causing the cloth to lift. There are still areas that are a bit dry. I am not expert enough to know if this is a problem.

Sunday, November 11, 2007

Floats repositioned for hull lamination.

I realized that the hulls should laminated before the decks so it was suddenly time to rearrange the floats in the garage. One float needs to hoisted up close to the garage ceiling and the other needs to be presented on its side. Like other builders I'm using form frames 5 and 9 to hold a float in this position.
To get the form frames into position one float had to take a break outside for an hour or so. Here is a shot of the float from above.
And from the side.
And with the new form frames in place, here is the new orientation.

This was also a good chance to give the garage a good sweep and clean up.

Saturday, November 10, 2007

Further comments on the 'plastic on peel ply' technique

I've covered the other bow cap now using this technique and I am noticing in some areas the plastic lifts during curing. The resulting laminate in these areas is dry. It is curious because I am sure I have the cloth and peel ply well saturated. I suspect these are areas where I have been too aggressive with pressure on the plastic. It is a powerful technique and overall I am extremely happy with the results. Wonderful adhesion with zero air bubbles. Just a few areas that I believe I can re wet out.

I am now moving on to the larger job of laminating the decks.

Thursday, November 08, 2007

Results of plastic on peel ply

Here is the bow cap with the plastic and peel ply off. The 2 layers of my B spec. 9 oz s-glass fiberglass cloth cannot really be seen. Only the little goatee at the keel bow curve indicates the presence of the cloth. I am actually very impressed. I will carry on with this technique. The addition of the plastic and the extra squeezing appears to really enhance the laminate quality.

The Mas epoxy seems to work OK. Curing time is shorter compared to the Aeropoxy resin and it is very clear. They advertise Mas as a good moisture barrier, which is why it is going on the outside. The Aeropoxy resin has amazing high temperature and mechanical properties which is why I have used it on the interior and structural parts of the floats.

I've been making extra efforts these days to do a little bit every day on the floats in the garage. So far a wee bit of heat from the infra red heaters is all I need. Last year I could work outside till Christmas time. I hope the weather this year is similar. I dearly want to get the outside of the floats laminated and start thinking about the main hull.

Wednesday, November 07, 2007

Plastic on Peel Ply

Final check on the bow cap shape. The picture shows how tightly the final shape fit the template cut into plywood.

As far as the fairing and shaping goes it got to the point where I just said - enough! So I cut the cloth, peel ply and this time a 'heavy' plastic sheet from home depot.

A comment that Biol made on Jay's site led me to investigate a technique called 'poor mans vacuum bagging'. This really just consists of applying a plastic sheet over the peel ply and using the seal to push air bubbles and excess resin out of the area with a plastic squeegee. I started a discussion on this on the F22 builders group site.

Here is my first attempt. There is a shiny clear plastic sheet over the black peel ply. In application it was not such a revelation. The plastic sheet does help to hold the laminate to the foam. However, the application of the two layers of my b spec. s-glass cloth applied so smooth and bubble free that I am not sure if the plastic really is doing much. There was one area where I did note excess resin getting worked out.

I also complicated the experiment by using a different resin. Now that I am laminating the outside of these parts I used a resin that

  1. Advertises good moisture resistance.
  2. Was on sale at Noah's.
The epoxy is MAS low viscosity resin with the slow hardener.

First complaint. The resin and hardener are the same colour. It is not so easy to tell when it is fully mixed. If anyone has any comments or experience with this resin. Comment away please.

My work place has moved and it happens (life is strange) that I am now about a 3 minute drive to Noah's Toronto main warehouse. Very handy indeed for quick lunch break supply runs.

U-Spar estimate on the F22 carbon fiber mast

I received a response from U-Spar at regarding my
inquiry for a carbon fiber mast for the F-22. They do not have a

section small enough for the F-22 although they would consider making
a mold for an order for 3 or more masts. They state that "Our masts
are made with alternating layers of uni-directional pre-preg,
typically with 65 - 75% of the fibres in the 0 axis, and the remainder
at + & - 45 deg. This combination gives by far the highest
longitudinal stiffiness to weight ratio, combined with high torsional
strength. Point-load areas, such as tangs, winch pads etc., and cut-
outs for halyard exits etc. are all substantially reinforced." But
they admit for a small mast they are probably not price competitive.
They estimate the price for a complete mast, including the rotator
cup, painted and ready to go, would be in the region of $8,750 Cdn,
with a 10% discount for 3 or more masts.

Saturday, November 03, 2007

Full Monty on the bow shapes

I'm sure I've related in earlier blogs that I have seen issues in the resulting bow sections after I joined the float halves. I addressed some of this as best I could earlier with light filler, as seen above, but it is time to pay the piper when your trying to get the bow caps shaped correctly. Root cause of the problem? I suspect there was an issue in how I laid up the foam in the frames and/or the halves twisted in storage outside.

So, how do I know I am shaping the cap correctly? Well first I used the two beam locating dowels to verify that the bow cap radius is dead ahead. Then I used a plumb bob to verify the position of the keel - bow radius. Then I used a straight edge to fair the bow cap to the shape of the float hull. This is where the use of filler comes in.

I ended up fairing the keel bow thickness down to something close to 3/8" thickness. This could be a bit sharp. At deck level the thickness at the bow is ~ 1 3/8".

Gunwales are close to finished. I found the use of the rigid long board helpful here. You can also see that my access hatches have arrived. I am actually pretty close to covering the bow caps, transoms and decks with the A spec. fiberglass. Yup, time to get the heaters out again.

Putty and cloth around the chain plates. I apply the cloth when the putty is still wet. Actually I saturate the cloth with the putty before applying it against the wet putty build. I'll clean it up when it's hard and cured.

Google group for F22 builders

I've created a google group for F22 builders.

I want to get this blog back on focus as a personal build diary. The group site can be the place where questions and discussions amongst the builder community can take place.

I've made the core group of the F22 build bloggers managers of this site so that there should be no delays associated with approvals and other administrative activities. I'm listed as the owner (I am the creator - sorry a joke from work) but the site belongs to all of us. If it works for everyone - fantastic. If it doesn't, well, as a wise man once said, 'not every effort can be a cracker-jack'.