Saturday, December 4, 2010

Sunday December 4th

This week we finished locking the deck beams in place. We tied the beams together with a 2x8. We had to put a jack post under the front two to bring them up to an even line with the deck.

We had to cut out a 3 foot section of deck the width of the engine hatch, to strengthen the repair. Lest their be a section of the deck with 3 foot deck boards. Noel has a hatch built into her deck between two massive timbers to make it easy to repower her.

The boards were #1 kiln dried pine decking boards as they are the clearest of knots and sap pockets. They also come planed to 1 inch. The boards on Noels deck were 1 1/8th red fir. We picked up the pace by not having to run all 35 1x6's through a planer to bring 2x material down to size.

Noel was planked by popping a string down the center of her frames, and laying a board to each side of the centerline, working out on each side to a distance around 8 inches from the edge of the deck where she had cover boards that were cut with notches to allow each board on her deck run out square into the cover board instead of tapering to nothing. This is called a gunstock, which looks like... well, a gunstock. This may be a local term, haven't seen it in a book.

This is the fastest way to deck a boat, as you don't have to fit all the deck planks to the curve of the outboard edges of her deck. Since her deck planks don't curve, they don't need a king plank in the center to allow them all to notch in full width rather than running into nothing, or alternating sides in a herringbone pattern. Just lay the cover board on top of the beams and scribe it from the inside, and the outside... flip it over and cut it.

We spread epoxy on the beams with an empty caulk gun tube.

We screwed down the 1x6's which we ripped to 1x5 so they would lay in Noels existing spacing without having to notch anything. All told we used closed to a thousand 2 1/2 inch stainless screws.

That concluded Wednesday...

Thursday we sanded 7 sheets of 1/2 inch marine grade plywood and started fitting them. We had some grinding and fitting work that took most of the morning so that the plywood overlapped and tied new wood to old. I ground an 1/8th inch off the existing boards to make everything kosher so that the plywood would lay to it.

We then ground off the heads of any buggered up screws, sanded the deck to take off any high spots in the planks and laid down and fitted our plywood.

I wanted to try drilling air relief holes in the plywood to see that the board was making contact with the glue as it pulled down. Normally we mix up epoxy with cabosil to peanut butter consistency and squeeze everything together with 1 5/8 square drive screws. The thick epoxy and lack of relief for the air means that the plywood doesn't always lay perfectly on the surface of the deck. On a side deck, or the tapering bow it doesn't make much of a difference when fairing for paint.

The stern deck is a wide and doesn't taper out much, I wanted to make certain that the plywood was pulled down to the deck boards so that the crown remained consistent everywhere. I slipped the same square drive screws through some 3/16ths stainless fender washers. (Stainless works better with epoxy, as it doesn't adhere quite as tenacious as it does to steel.)

This is how we laminate transoms, and did the section of the back deck last year.

I spread thickened epoxy on the deck, and the plywood with a notched spreader.

It took a little more than 40 ounces of mixed epoxy per 4x8 sheet of plywood. I mix out of 5 quart mixing buckets on projects this scale. It took 48 ounces of cabosil per bucket to make a mix that just would stay up in peaks after it I spread it, but no thicker. To thick and it makes it hard to get the panels to fit in place. I lay one side of the plywood going down against the sheet that is already glued, and kick it into place with the cleated heel of my boot. If it is to tight, or won't go... a block of wood and a hammer. Don't hammer on the end grain of plywood it splinters.

We fit each of the plywood sheets in its home, and put black marker lines across each of the seams taking up one row at a time to glue, leaving all the rest in place. You get some glue on the next row that is currently dry, but everything goes together perfectly without having to sand or cut off pieces that no longer fit. We staggered the joints so that there were no straight lines across the width of the boat, which is much stronger than just laying the sheets where 4 corners come together.

From there it was a matter of screwing everything down. Fender washers make life easy... Lay them all as pictured in the photo stacking up with a width just wider than your fingers. With your hand palm down swoop in and grab 5 or 6. Flip your hand palm up, and start your screws between your fingers. This is the easiest way to do the job. (see pictures)

I put a screw about every 10 inches square, and added one here and there along the edges to pull it where the seams are smooth.

Since it was 44 degrees today, I was using Fast hardener. I had a big kerosene wick heater under the deck cooking for an hour or two, until the deck started to warm up. It took two heat lamps to bring my resin up to normal consistency... 60-65 degrees. To much hotter than that and fast goes atomic before you can work with it. I used 4 mixing pots, just for resin so I didn't have to heat all my resin, just what I was about to use. Boat projects don't feel wind chill... but it did make for a long Saturday for me!

Thats all for now...


1 comment:

The Rudstroms said...

Thanks for the neat trick about how to pick up screws.