Reply With QuoteSteve, I believe Horse was referring to bridge clearance.Originally Posted by Horse
It`s looking good so far,
great job!
please keep us updated with the project
Yeah, thats what I was thinking. Everything changes, especially the costs for trailering and tow vehicles.
Steve, I believe Horse was referring to bridge clearance.
It`s looking good so far,
great job!
please keep us updated with the project
Bridge deck clearance in the specs is the distance at rest from the water to the top of the tunnel between the hulls. Some cats are designed to ride on this bridge deck, others use the air pressure between the hulls to provide lift. This cat is designed with sufficient clearance to ride over the waves and minimise slamming of the waves against the bridgedeck.
Steve
Long life antifouls have been created by mixing copper microspheres in hard wearing epoxy. It is this technology that I have decided on for my project. Details can be found here: http://coppercoat.com/ Called a 10+ year antifoul, Coppercoat does require periodic "scrub down" to remove the slime. My thought is that because my boat will sit only 8" in the water, I'll be able to do my scrub downs in a shallow bay and avoid some of the annual haul out costs. I still plan to build a trailer to take trips with the boat, but that project is after building the boat itself
My underwater area is about 14 sq metres and that reauired 3.1 (read 4)litres of Coppercoat, consisting of 4 litres of expoxy and 4kg of copper microspheers. These are mixed together to get the copper "in suspension" and then painted on with a roller. The copper colour changes to a greeney vergreis colour over time.
I drew the antifould line 75mm above the designed water line (DWL) using a water level. I then applied 3M 'edgelock' masking tape. Coppercoat requires 4-6 layers applied wet on tacky. The pot life is only about an hour so I decided to mix 1/2 litre per batch since I was working alone. This batch size allowed me meter out the coverage and to paint either the insides or outsides of both hulls without too much climbing. In all I got on six coats over 12 hours, finishing night before last just past midnight. The next morning about 6AM I went out and removed the masking tape before the epoxy had time to harden.
I'm really happy with the way this came out and I know that no algae will grow on my boat (as long as it stays in the shed.) The next step will be to paint the area between the hulls then flip the boat over and start building out the inside.
Looks great!
Cheers
Chimo
What could go wrong.......................
Looks good and hey Steve don't forget you still need to build a dinghy out of all the leftovers. I need a strong lightweight dinghy so I may come and do a double cat dinghy build!.
I'll be really interested in how the antifoul goes. How much did it cost and how much coverage did you get from mow much of it?
The lighter weights are going to make you a easy tow but you may have to check the aerodynamics so it doesn't take off and leave the road at that weight and nasa will be in contact.
For the trailer before you turn it over I wonder if it is worth just taking final measurements of the hull bottom for when you do the trailer build.etc. At a lighter weight a alloy trailer will be a good option and less maintainance for occasional usage.
Hi guys, Cormorant, the antifoul was $775 but that incuded $110 transport for hazardous material from Freemantle. By his calculations I needed 3.1 L for 4-5 coats to cover 14 sq m. When I started, I was worried that I'd put it on too thick and not have enough to get the number of coats, so I actually got two complete coats out of the 1st litre. I started putting it on a bit thicker and was still getting an extra hull per litre. I got at least 6 coats in total.
I hadn't thought about a dinghy cuz I've already got one but come to think of it, I'm going to have a bit of extra material because I told them not to cut out the seating for the cockpit (the design had seats all round and I thought they would get in the way when fishing.) My thought was to build two custom ~4 foot long ice boxes with padded tops. These could sit along the gunnel when cruising and be pushed to the centre when fishing. Any ideas on that and how to keep them in position?
The designer does have a design for a dinghy but it's very expensive. I saw a Peter Snell (Easy (sailing) Catamarans) designed cat dinghy and took lots of pics and measurements of that. A cat dinghy wouldn't be a bad idea given the number of people who have drowned recently going from the dinghy to the boat!
I'm also thinking about trailers. Luckily, I've got my mate in Swansea who had one build by Feld in Newcastle and I've been all over that with a tape measure and for ideas. I'm on a bit of a tight budget for the boat which is why I am deferring the trailer until after launching. With steel, I could build it myself (hiring a qualified welder.) Not sure about self building with alloy, but that would be ideal.
Steve
Painting the Tunnel
After applying the Coppercoat antifoul and letting that cure for 10 days, we painted on three coats of linear polyurethane, using the 'roll and tip' method. This is where you apply and spread out the paint using a roller, then "tip it off" using a fine bristle badger hair brush. This is a very fine, once over, one direction stroke with the brush. This allows the linear polyurethane to 'flow out' into a mirror like finish which you'll see in the pictures. In the first coat we mixed the paint and let it sit for 30 minutes before adding 33% thinners and rolling it on. More thinners were added as time passed. This coat, done by Phil came out perfect as you can see from the photos.
Second coat, done by me came out totally fecked up with brush marks everywhere. The mistake I made was I added the thinners right after mixing. They must have evaporated off during the sitting period because the paint just didn't "flow out" even though more thinners were added as time passed. Needless to say, this coat required a great deal of sanding and the application of a third coat of paint.
After painting the tunnel, I crawled under the boat and cut out the build jig. This was a lot of cutting as there was a full width temporary build frame every 800mm. I finally found a use for my dual saw! Early on, before putting on the sides of the boat I had got under there and taped all the chines except the 100mm or so right above a frame. Once the build frames were removed I was able to get under the boat and fibreglass all the chines where the frames had been plus the whole forward 1/3 of the boat which was inaccessible, plus the inside chine formed by the hull side. That completed I gave everything a good sand, did a bit of in-filling over any rough spots and jacked up the boat in readiness turning the hull. In the final pictures you can see what it looked like under the boat.IMG_0416.jpgIMG_0417.jpgIMG_0459.jpgIMG_0461.jpgIMG_0455.jpg
Getting there Steve. Was it easier to glass the inside from underneath or were you adding strength before flipping it?
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Both, really. From having worked on the tunnel for so long I was soooo tired of working below my knees. It was such a relief to stand up straight! But also for strength. The hull sides which went on last had only been taped on the outside so those needed doing on the inside, and also the bows where all the pieces come together. It was just so easy doing it sitting down or at shoulder height that I did the lot!
Looking great! How are you going to turn it over? Is it going to sit on a trailer or flat top to complete it?
C
C
What could go wrong.......................
Chimo,
Usually you drag it out of the shed and roll it. That requires leaving in several temporary MDF bulkheads to support the sides which are long and floppy. Because I had several weeks before I could get a crew together, I decided remove all the temporary bulkheads and do all the inside glassing while the boat was upside down. Also because I had built the 3-ply transom and the motor wells which are normally done after the boat is flipped, the stern of my boat was much stronger than without the transom and so I decided (in my infinite wisdom) to flip my boat end for end. Little did I realise that 2/3 of the weight of the boat would be "over-head."
Anyway to protect the duckboard I placed mdf boxes under the motorwells and cushions on each of these. The thing I didn't count on was that this raised the whole monument another 400mm AND the cushion on the MDF was incredibly slippery (both going up and coming down.) I had lifting and lowering ropes attached to the bow on both sides. Because this was SO unstable up in the air, the photographer was called to grab a rope. In the middle of this we had to tie additional ropes to the duckboard to stop the stern slipping (both going up and going down.) The wife of one of my mates was taking a movie with her iPhone and I managed to capture this image from her 7 second video.
As you can see in the previous post, I raised the upside down boat in the shed high enough to reverse a car float under it. We then lowered it down onto 4X2 bearers After it was raised to vertical (higher than the peak of a 2 storey house) we lowered it back down onto a waiting mattress. All went ok without mishap. As of today it is back in the shed on the custom built stands (3 to a side) that come with the kit.
I'll put up more pictures later
Steve
Yippee ky yay, currumba; lucky!
I thought that us GOMs all like a quiet or at least very well controlled life!
Very glad you pulled it off so to speak. Tough stuff that plywood!
C
C
What could go wrong.......................
Turning The Boat
The day did not start well. We arrived at the shed missing one of the wheels from the trailer. Undaunted, we pulled the upside down boat out of the shed and got the bow up on stands. We placed more boxes and cushions under the motor wells to protect the duck board when the boat was vertical. More cushions and a queen mattress were placed in the fall path. When we finally lifted the boat vertical, it looked like a pair of Washington Monuments. The lowering was safe and steady with only a slight thump at the end. The boat easily slid onto the trailer for the ride back into the shed where we placed it on the pre-made stands. The following day, I build stairs for both port and starboard sides. Since the boat "just" fits in the shed, this lets me access either side of the shed from the boat.
Might not have started well but the product as slid back in the shed is a credit to you. Well done so far, looking forward to the topsides and the fit out.
Cheers
Chimo
PS Good thing the ground was dry and hard for the flip.
What could go wrong.......................
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