the basics

After a couple of years of laying glass, I've settled in on a very effective method of performing a surface lamination over core cell foam. Here are the simple steps that I use:

1. build mold
2. fasten foam to mold
3. skim coat the surface of the foam w0 micro and epoxy
4. let cure to the touch and rough sand any slight imperfections
5. roll out a good wet coat of epoxy using 3/8 Knapp half roller
6. roll out glass
7. roll top coat of epoxy and let soak down into the epoxy that is soaking upwards
9. roll on the peel ply
10. use bondo spreaders to smooth out excess resin in the direction of lamination.......do 3 to 4 ft sections at a time moving in one continuous direction.

works for me........

glassing the bridge deck

rolling out 32 oz. triaxial glass onto the bridge deck.

Bridgedeck floor

I've added curved mold forms to the side of my vac bag table to form a mold for the bridge deck. This will allow me to create the forward portion of the bridge deck.

Aft bridge deck

Here is the center reinforcing rib that provides rigidity to the aft bridge deck floor. It's ready to pop out of the bag.

1500 Watts of power

The cold waters of the Columbia river turn huge hydroelectric turbines and the wind flowing across the ridges out east are spinning 300 ft. blades that combine to create electricity to cure my layup.

plastic pup tent

Since it's sort of cool tonight, I used a board turned on edge as a ridge pole to create an enclosure over my vac bag table.

about to close the bag on the aft bridge deck floor

Here's another shot of the bridge deck floor. I'm about to seal the top bag together down the middle to form an air tight bag.

A sample vac bag layup

Here's an example of my vacuum bag process. I'm using my 8ft. by 12ft. rubber sheathed vac platform to create the flat aft portion of the bridge deck. This particular section has an angled portion that transitions into the floor of the interior bridge deck so I've used a filler block to create a solid lower surface to vac bag against.

centerboard case sides

Finally.......all four centerboard case sides out basking in the yard.

The wide ones become the inboard case sides. Notice all the reinforcing ribs and high density top edging. I decided to use Luann Mahogany for the high density core edging along the top portion of the case sides.

infusing a portion of a centerboard case

Sometimes it's a toss up as to when to use the resin infusion process. In some cases, a controlled infusion of resin can be a good way to insure a strong part. Other times, it can turn out to be a big waste of time when the same thing can be accomplished with conventional wet layup w/ peel ply or vacuum bagging. One nice thing about the infusion process is that, if done properly, it can be a neat and clean operation.

Clamping things with clamps

a man can never have too many clamps......

center board cases

Here's on of four centerboard case sides being fitted with various high density edge cores and extra glass. I'm using a medium weight Luann mahogany for my "high density core material. This top case edging will be covered with 32 oz glass and vacuum infused.

Bagging the inner, port centerboard case side

Since my vac bag table spent the winter outside in the rain, I had to spend a little extra time preparing it to be used again.

This time, I screwed three full sheets of tongue and groove 3/4 in plywood to a framework of 2x4's and sheathed the whole thing with a 15 X 9 ft. sheet of thick rubber pond liner. My logic here is that I only have to use one sheet of vac bag every time I create a part because I am able to simply seal the top membrane to the lower rubber sheet and use it over and over again. By placing the entire platform up on a few sets of car jack stands, It also provides a nice comfortable , clean work surface.

In this photo, you can see the yellow rubber vac bag tape along the edges of the rectangular vacuum bag area. Also, here are a few more things to notice:

the vacuum manifold can be seen inside the bag on the left. To distribute the vacuum pressure, I use a 1/2 in piece of plastic cpvc pipe with lot's of holes drilled in it. This gets wrapped in breather material and insures that good uniform vacuum pressure is maintained along the entire part.

center board blanks

Time to shape some surf boards..... These things are almost 10 ft long. The upper board blank is still in the bag that I used to vac-bag all the foam pieces into one big board. If you look closely, you will notice cross cuts in the board stringers. These cuts were made to help me gage the thickness when I go to shape them down to size. ( before I bonded all the foam in place, I used a skil-saw set to the precise depth that corresponds to the thickness of the boards called out in the plans.)

laminating the centerboard stringers

Inside of the twin centerboards of this cat will be the most beautiful lightweight straight grain mahogany stringers that the world will never see. Here, I'm using a vacuum pump to help laminate two sets of four 8 inch wide by 78 inch long boards. These boards will then be shaped and then bonded with 45 x 45 x 0 glass and will become stringers that will then be embedded into two separate foam blanks. These stringers will then be shaped and capped with multiple layers of unidirectional glass and the sections that will swing down into the water will be shaped into symmetrical foils.

The next blue sky will find me shaping them with my power planer like two big honkin surfboards.

Varifying the varifications.....

It's always good to have someone check all the layout dimension before taking a power planner after anything. although it's always possible to glue foam back into place if you make a mistake, it can save some time. Here, the inspector is checking the location of the centerboard pivot pin. He has also made various marks on his legs........perhaps to test the functionality of the writing instruments.

the boards

So here's the full size template of the centerboard. The gap in between will actually measure 27 inches and both of the templates are seen here taped onto a 4 x 8 sheet of core cell.

The plan is to slice most of my scraps into uniform widths, laminate them into a 4 sheet thick plug and vac bag the block into one solid blank. Various sections are comprised of high density material ( I'm planning on using straight grain 1/4 sawn Douglas fir for the internal sheer portion of the spar. Since this piece is going to be encapsulated thoroughly and capped with multiple layers of glass and epoxy, I will not feel that bad about using wood as an internal spar.

Next comes the fun part. The plan is to build a 3D Cad file of the boards and have them cut on a CNC router. If it was summer, you can bet I'd have these things on a couple of saw horses in the sunshine and just shape them with a power planner like two long boards .

Soulfull tools

Special thanks to Barney of Hood River, Oregon for passing along his Grandfathers saw. I think most good tools seem to hold the presence of past owners. This is a good because table saws, in particular, have been known to throw things across the shop for reasons unknown to the living. New table saws do not come with the watchful presence of past owners.

It's good to know that Barneys grandfather and I will both be watching out for my fingers.

"Center" board cases

Although it would certainly be easier to fit this ship with dagger boards. I like the idea of making sure that when she runs aground, the boards will simply kick back into the hulls. Here I've lay ed out the board case sides and have pre-cut all of the High density foam inserts that become integral parts of the case sides.

The case sides are comprised of 3/4 in. 5 lb. corecell with various inserst of 12 lb. foam to strengthen high stress points.

Doubling up the sternI uI

 
 This first photo shows the extra pieces that I have cut to add thickness to the hull stern flanges. Notice the slim crescent shaped flange thickener that I have preformed to fit the trailing edge of the stern.  

Here's a shot of all the pieces after they have been bonded in place. I used a v grove flooring adhesive spreader to coat the bonding faces with a generous amount micro thickened epoxy.