Built a mold.

I spent some time building a mold off the hatch cover on Pylasteki last week, for practice and to make a spray hood.

I've been reading a lot about mold making, and polyester based products, as I don't have a whole lot of experience outside the realm of epoxy.

I sanded off all the old paint down to the gelcoat, and faired the top with a polyester fairing compound, akin to the infamous "bondo" but different brand. I long boarded with 80 grit, and worked the lows to shape.

I then applied a skim coat of 3m's Pirranah finishing putty, and sanded with 120. The last of the pin holes I filled with Evercoat's Ultrasmooth finishing putty, applied with a razor blade.

After that, I acetone washed everything. I scuffed the surface with 80 grit, and sprayed 15 mils of Duratec Surfacing Primer, and let it sit. I used a mil gauge to verify.

In the morning, I wet sanded with 800 grit all of the orange peel. I buffed it with a power buffer (Makita 9227c) and Aquabuff 2000. I goofed, and got saw dust on the buffing pad... some swirl marks.

After that I washed it with soap and water.

A few weeks ago I took two pieces of dura-rock tile board and epoxied them together on the top of my table saw, and contact cemented a sheet of formica over the top. I used this as a mold plate by placing the hatch lid on top.

I took plasticine modeling clay and filled all the cracks against the formica, and filled the openings at the front, with clay and smoothed it out as best as I could. Then I cleaned up all the dust around, and applied 3 coats of honey wax, a mold release wax.

I came back the next morning, and buffed off the wax and put on one last coat.

With that done, I got out mixing buckets and some black CCP sprayable tooling gel, catalyst, and stir sticks. I pulled out my binks 95, and put my biggest tip in it... catalyzed the gel, and put it in the cup, pulled the trigger... and nothing happened. It is a siphon feed gun, but would not pick up the tooling gel! (Will have to make an attempt to re-create this...)

So, with tooling gel that has a 15 minute pot life, I grabbed my junker hvlp gun with a 1.5 tip, and cranked up the air pressure to squirt it through after quickly tearing down and making sure it was clean. At this point, there wasn't much pot life left. I sprayed what I could, catalyzed another 16 ounce batch and sprayed almost all of it. before it gelled up. This resulted in just over 15 mils of gel. Ideally a mold would have 20-30 mils, but I decided to proceed with the thinner coat.

Thin gel coat, can alligator, or shrink and pull loose when you lay over it with the first layers of mat. I have seen pictures, so I wanted to see if it would happen for the sake of education... it didn't.

4 hours later, I came back and laid two layers of .75 ounce mat over the part. No scissor cuts, just tearing the mat off the roll so that the layers would blend together.

The next day I came back and laid 3 layers of 1.5 ounce mat, and the day after three more. When the last three layers had hardened, the mold broke loose from the formica sheet, so I decided to de-mold the plug (the original hatch cover)

I used plastic mixing sticks, and plastic squeedgees, and in a few minutes time it was out.

Then with a jigsaw, I cut the excess from around the edges with a jigsaw equipped with a diamod grit blade. It worked like a champ, until I hit an air pocket that was longer than the blade could cut without hitting the bottom of the pocket, bending the $12 little bugger... I switched over to a metal cutting blade.

Ideally when the glass is still "Green" and hardening but not all the way kicked you cut off the overhanging edge. I left each layer alone, as it was sitting on top of my table saw, and didn't want to blow fiberglass dust everywhere.

I will make a spacer to go on the flange around the mold, about an inch thick, and round it over. When I lay up the part in the mold, it will work as a sea hood, that happens to be the same shape and style of the original sliding hatch. Lots of work to build a sliding hatch, but the education has been worth it.

Zach

Last weekend...

I spent last weekend sanding off the last of the bottom paint on Pylasteki, as I'd grown tired of pulling up beside a boat that looked like that much of a project...

This week Noel has kept me busy, and a wasp nest was formed on my staging that I kept forgetting to purchase wasp spray to correct...

Yesterday after work I pulled out my outboard, and did some measuring to see about an outboard well, instead of having it hang off the transom. I spied a picture of Bo Mann's Triton on the Plastic Classic discussion forum with a well in a Triton.

Seeing as I'm in the process of cockpit and lazarette construction I figured it would be best to set aside all prior plans and design around an outboard well. A: It sure does look better than being hung on the transom!

Pictures

Saturday I spent some more time grinding out old fiberglass tabbing under the old V-berth, and a bit of sanding of old bottom paint.

I put another layer of tabbing across the bridge deck, and tabbed the bulkhead to the underside of the deck at each side. I pulled down the backer board under the starboard side deck repair, and added a layer of glass to the underside overlapping into the original deck.

May 24, 2011

Sunday I spent the afternoon fine tuning the bridge deck blank ( a 6 foot x 27 inch piece of 3/4 divinycell glassed on both sides with 1708 biax and epoxy.)

I cut the top of the bridge deck bulkhead off level. I cut the lower lip remnants of the back of the cabin off, and ground the gelcoat off so the flat foam panel would fit up tightly. I screwed a piece of 3/4 plywood across the back of the cabin to hold the existing fiberglass to keep the opening true.

Once the foam blank fit nicely, I rounded it over with a router to ease in the glass work.

Then I ground off all the gel coat around the cockpit sides, where the coaming boards attach so the new foam and fiberglass will be firmly attached. I left a small lip of the old cockpit seats to have a support for the new work, and to keep the side decks from deforming.

Then we went for a sunset sail on the tanzer.

Monday was a no-boat work day.

This afternoon I double checked all the past work, and finished grinding the inside edge of the cabin wall.

Then I ground out a bad spot on the starboard side deck, where in the past a stantion had been ripped out and a polyester repair was made. It was a bit of a soft spot, so while I had access I ground the old out and glassed in three layers of 1708 with epoxy. I used blue dow board foam, and a few dots from a hot glue gun to hold the backer in place. I wanted to fix this spot before the new bridge deck went on, and it made access to the underside more difficult. I will be glassing the bridge deck bulkhead to the side decks, and making the bulkhead water tight.

While the hot glue gun was heating up, I walked down the port side deck with 40 grit on an 8 inch pad sander, where I had applied fairing compound over the weekend.

Next I acetone wiped and sanded off the foam board and edge around the cockpit. I mixed up some epoxy, and painted it on the edge of the foam and all around the cockpit lip. I took the extra, and put it in a bigger mixing pot... mixed up two more little batches and added cabosil (fumed silica) to thicken the epoxy to peanut butter consitency. Then I took the mix of glue, and piled it up on the lip around the cockpit edge and smushed the new bridge deck in place. I filled the gap around the outside edge and worked out all the air, cleaned the excess and called it a day.

I also... forgot my camera.

Zach

Update: May 21 2011

Over the last few weeks of afternoons I've reworked how the boat was blocked and adjusted the stands until she was level. I also put the finishing touches on the foam hull coring on the Tanzer 16.

I glassed in the foam on the top of the cabin top.

I sanded off the port side deck and applied some fairing compound.

I glassed the interior side of the bridge deck bulkhead, and tabbed it in place.

I removed the rudder, and spent some time studying pricing on replacement shafts as the bronze has gone pink. I am planning to use a skeg style lower bearing, and a full length shaft. (Pylasteki has an outboard engine, and I'll be filling in the prop aperture.) I'm also looking into replacing the rudder tube with a larger diameter, to be able to fit a cutlass bearing to take some of the play out of the system. Pylasteki's rudder is the original, best as I can tell that has been fiberglassed over.

I bought a used monitor wind vane (Thanks Tim! www.lackeysailing.com)
And snagged a Whale Gusher 25 bilge pump at a second hand store.

Zach

Pylasteki Moved...

Wednesday I had Pylasteki moved from the yard she was in, over to the one where Noel lays along side to be closer to my floating work shop.

I spent yesterday afternoon blocking her up squarely as the hydraulic trailer couldn't rotate her far enough up in the bow to set her down right. This took some time...

I spent this afternoon building scaffolds to be able to work around her.

Tomorrow I have one more scaffold to build, a few saw horses to lay down the mast and a little work bench as a prep spot. My ladder is now a touch short, as the boat is now about a foot off the ground instead of 4 inches like at the other yard.

Progress!

Zach

Grinding!

Yesterday I ground the gelcoat off the top of the cabin top with an 8 inch pad sander and 40 grit. I am always surprised by the thickness of the gelcoat on Pylatesteki. She has one full coat of cream colored gel over a full thickness coat of black gel, and it is hard as nails. (though cracked and crazed like a broken egg shell...)

I have decided to leave the hatch rails in place for the moment and core the outboard sides of the top, before the rails come off. I am not sure how much influence the rails have in holding the top straight and true. There is a chance that removing them without adding back something else will warp some lumps and bumps into the top.

I ground 1 1/2 inches around the new foam, and set the foam 2 inches away from the edge of the cabin top on all sides.

This way I can bevel the foams edge, and laminate new fiberglass on to the top without grinding the sides of the cabin, which requires grinding a recess greater than the thickness of the two layers of cloth that will be going back in order to fair back smooth.

I'm going to build up the perimeter around the foam with strips of scrap fiberglass to within an 1/8th inch of the template I made of the existing corners. I'll then use some epoxy putty fairing to pull the edge into a smooth slick surface in 2 or 3 coats, using the template as my spreader. This is faster than shaping the fiberglass its self into the perfect shape with a grinder or 36 grit, with less damage to the cabin sides.

The solid fiberglass edging will keep stray anchors and heavy stuff toted on deck from crushing the top skin over the foam, which otherwise doesn't take point loading very well.

I ran out of bricks (I thought 14 would be enough...) to hold the foam down to the cabin top. I normally use a heat gun to relax the foam a bit, but forgot to bring it along.

I used some of the pre-existing holes for winches and turning blocks to jab screws into the foam to lock it in place. My drill was with my heat gun... It works fairly well to run a sheet rock screw through the foam into the glass behind it when gravity doesn't want to co-operate.

I left the screw holes open, even though some glue will drool through I did not want to bond the inner skin to the outer skin, as I'll be removing the old coring and inner skin and old balsa for more head room.

Cheers,

Zach