A Few Layup Questions

Rolling a of the sheet of glass from the second layer into the hull, onto the first layer. Looks like this was the last sheet, since the sheet on the right side of the mold has already been unrolled.

 

Quick follow up question on the method, Andrew:

I had decided to start at the bilge, rather than the deck curve so I could physically reach the bilge area.

If I did the topsides first, I cannot reach over the forms into bilge (from the left side of my mold in the picture) to access it for squeegeeing. So, I took your method and varied it ever so slightly... by doing the bilge first, then the topsides and then lastly, the deck area by standing on the already glassed topsides.

Is there any reason this would not work?

Because I cannot reach the bilge area, this seemed like the most logical way to reach all areas.

Gonzo: The West epoxy has a viscosity of 1000 centipoise. The System Three has a viscosity of 650 centipoise. I think the System Three is better for soaking into the heavy triaxial, no? I already bought it, anyhow.

 

Cat Builder - I'm not sure, but you may have been replying to my post previously thinking I was Scott? No worries, just making sure I'm replying correctly.

I don't think you will have any problems at all laying a single piece the entire length of your mold. I haven't worked with the heavier triaxial, but if it is any thing similar to my 18oz biaxial you'll have plenty of time to get it done AND do dinner and a movie (or some such activity). I expect there will be no pleats - once the material is wet it fits into the mold nicely - should I say like a "wet tee shirt"?

For me, I definitely would NOT wet out on a table in advance. Big pain. For what it looks like you are doing, I'd wet the foam out real well, then put the material on top of that and finish wetting the material through from top. If you're in doubt, try a sample piece of glass with your epoxy and see if it will soak through from the top. It should do so easily if your using the right viscosity.

By the way, I prefer my second layer of glass because it sticks to the first layer which is still wet; this seems easier to work. Since you will/should wet your foam first the glass should just lay right on also.

When laying dry glass onto a wet surface - the first couple of minutes are critical. The glass is still dry enough you can kind of lift it and "flop" it a little bit to reposition - but once it is wet you'd better have it where you want it. It'll still move, but not as much. Working quickly, I've set dry glass on wet epoxy surfaces, then lifted it up and repositioned, then reset it once or twice. If done quick enough it is a very effective way to position the material. Once done, it gets a partial wet through from the previously wetted surface, then the final wet out is a breeze.

 

If you strip plank then you can start at either end.
If you use transverse blocks for the topsides then better to start at the deck line.
To do the deck its better to use stands on the outside, also this being a narrow area and on a vertical pre-wetting out the glass on a sheet of plastic first is best.

 

Thanks Brian (not Scott!).

I was talking to a Scott earlier and with the brain on full overload trying to absorb all that I can here, I got mixed up. Sorry about that.

I'll certainly be doing some couple feet wide practice samples before this layup, including trying out the thickened epoxy on the foam vs neat epoxy along with destructive testing.

Seems most catamaran designers are suggesting this thickened epoxy coat. Mine does.

 

Cat Builder - regarding reaching the bilge area - this is why I use rollers. If you notice I have extension handles on the rollers in my first photo. My wife is 5'4" and with the extension she can easily reach down into the bilge area.

It doesn't take a lot of pressure - gravity and capillary action with the glass/epoxy does most of the work. The roller mostly just smears it around.

After the glass is in place I work the entire thing with a metal roller to ensure the epoxy is well distributed. I use a little more effort/pressure for this.

 

Cat Builder - regarding thickened epoxy -

If I understand your planned technique, it is to apply the glass directly to the foam? If this is the case I don't know why you would use the cabosil/epoxy thickened mix. I only did this because I was applying contour foam onto glass. The thickened epoxy helps stay in the kerfs and stick the foam on. If I'm correct about your technique, do not use the thicked epoxy. Just lay the glass straight on the pre wet foam, the finish wetting from the top. Finalize with a steel roller, then walk away.

 

"Destructive testing" - ah; now there is a topic I've been thinking quite a bit about.

One of the things I didn't mention about my several week time gap between my initial 80% of foam and remainder, is I had to convince myself the stuff was really sticking.

I hesitate to say I went back into my mold and used a hammer and chisel on a few sections of foam, just to see. Other days I took some of the trimmed scraps from my bulkheads and busted them up in different ways just to see what they would take. I even tried using epoxy on sanded, unsanded, peel ply, and other surfaces.

 

Sorry... have to keep asking...

Is there a problem I would face staring at the bilge?

I'm trying to do everything the most simple way and getting staging is both expensive and time consuming.

I had asked on the forum a while back about standing on the already-done topsides and I think everyone gave a green light on it. They said just to be careful of contamination. I would put a piece of thick poly sheeting down and walk (carefully) on that.

I'm definitely doing the transverse foam and already have the mold made up for it.

 

But how do you squeegee off the excess to get a good 50/50 resin/glass ratio on an area you can't reach?

 

Resin runs to the low point in the bilge. When it builds up enough I squeegee/scoop it out. A little left in the bilge doesn't really matter does it? A few pounds at most.

Although my wife can't reach that far, I'm 6'2" and if I stand on a step, and reach really far I can get most of it.

Honestly though, I'm not to worried about a little extra resin. Doesn't detract from the overall strength, and by the time the boat is done the resin mentioned in the bottom of the hulls will be insignificant and unmeasurable.

The beauty of the Woods Design is that after I get the round bilge part complete - which is the part below the knuckle - everything else is flat table work because they are single curvature panels.

 

Regarding starting at the top sides -

First I must say I haven't studied your build or techniques, and I am only a beginner. Take everything with a grain of salt.

I find I like to tackle the worst glass areas as early on as I can, that way extra resin can be pulled down into easier, flatter sections. Because of this I might be inclined to do the topsides first?

Perhaps lay all the of the initial glass in the mold, including the section that goes up the vertical topsides. Then buy a couple of sheets of white board and cut into two foot wide strips, and place them in the mold, on top of the glass that sets against the hull side. Fold the glass that goes vertical to the topsides over onto the white board and wet it out. Then tip up the white board and press it against the topsides mold and toss the white board aside or further down the mold out of the way. Smooth out the vertical glass and start working on the hull side.

Start pulling the excess epoxy down onto the hull side glass wetting it out and finish that glass? (careful not to pull the glass of the top side).

If you wanted to finish the rest of the glass down to the bilge, you could have it pre-cut and duct tape it to the edge of the bilge side of the mold and leave it hanging outside the mold out of the way. When the top/side glass is done, flip the bilge/side glass up on the work area and wet it out from the bilge towards the center of the hull side (after getting it stuck lightly in place with the correct overlap to the other piece of glass).

As you work towards the stem or stern, continue pulling the excess epoxy that gathers in the low spot down with you. When you get to the end there should only be a little bit to clean up?

If you end up with too much epoxy in the middle you might be able to soak it up with some excess bleeder cloth?

All of the above being said with the assumption the foam is pre-wetted. Maybe pre-wet the vertical topside, apply the glass, then pre-wet the hull side work area.

I also gotta continue to emphasize - I am only a beginner and am unfamiliar with what you are building.

If this approach works - you get the first strip of glass done and can make a decision - all well and keep going, or "bank" what you have and stop.

Using a stool you could work from either side of the mold?

 

Brian answers alot of questions cat, I feel better. rick

 

Simple you do not put it there to begin with,This is the reason I use a pressure fed Roller,large areas can be covered quickly ,Now on a heavy single laminate or multiple layers, we message the dry laminate in place then pull/fold back half the length to expose the core (when working short handed)then back-wet and drop the fabric back in and finish wetting it out,

a long wand handle on the resin roller has a good reach and is comfortable to work with, then do the same with the last section, I keep a few rollers in a Acetone bucket within reach of different diameters and length and brush rollers as well, By the time you have it wetout, the resin roller has done most of the work and a few passes with a metal roller generally has it in good shape.

 

All of the above I concur (except pre-wetting for this project)! I think I threw away all of my metal rollers. Foam rollers have a beautiful way of sopping up excess and applying it where it needs to go. The power roller is a great idea! I only use the squeegee when I get really carried away. Normally, I despise pooled resin, but if the boat is level, a little pooling (enough to fill the weave, not much more, IMO, is a good thing. The nooks down there will be easier to clean after. Make certain that the material is not floating. War Hoop knows what he is doing. All of the above is good learning material. Your resin choice is good, it's what I use and like. Set the fast hardener in another building unless you specifically need it for something. If a helper looks at it while you are doing this, you'll be hating life. It must be wierd to work in that warm, wet climate. Here, I can work all day in a nice, cool shop with a wet edge then crank the heat and go home.