Building 23' catamaran. Build updates

[stevemid]

Hi Chris, I was thinking of doing them one coat after the other (wet on tacky) to get the chemical bond. Any tips in that regard? I'm kinda worried about what 4 coats rolled on will do to my fairing job?

The area where I needed the bigger torture board was on the bridge deck. This starts out at 450mm wide then curves out 2m to meet the tips of the bows and up 1.2m to meet the deck. Fairing that was a ball buster. I should have beaded it first, but instead I used 2mm battens to lay down a 2mm layer of bog and then had to sand the whole surface of that on the 1st go. Phil came in after that andbeaded it with a notched trowel. He then sanded the tops of the beading fair and once that was done, troweled bog on using the faired beading as a guide. I'll still get to sand that but it should be just a touch-up, I hope.

Steve

[stevemid]

Removed duplicate post

Steve

[Nathan Tuskes]

its good to see someone else enjoying the fairing process as much as i did.... then theres the moment just when you think your done fairing you go to blow if off and you see a few hundred tiny pin holes.....you have to love using a 1100mm torcher board with 40grit....i only managed to do 1-2min stints before having a break....ahhh the pain...

[chris69]

Hi Steve,yer id be worried a bit too, if you going to roll that migh be your best option and do one coat across the hull and let get tacky and the next one coat along the hull and so on ,you will have to sand the last lightly no use putting it on to sand it away and it should stay fair as you have done a lot of work to get it good and fair,and if your useing a highbuld primer before you antifowl under the waterlin of the hull as you said you were going to do the highbuild should fill anything and beable to be sanded fair again a lot easyer,have fun, i hope it all goes well for you Steve doing the barrier coat,cheers chris.

[stevemid]

Hey Nathan, Hi Chris,
Yep, lotta work but if I don't get it right at this stage then no matter what equipment or glitz I tack on later, it'll still be crook underneath. I'm even thinking of bringing out a painter/panel beater to look it over before I paint. They have a much more experienced eye when it comes to "fair."

Chris, did you see the video of how Dean turned his hull single handed? Inspired!

[chris69]

Yer Steve i did and he is a good thinker, i got insperation form Dean after seeing it done so i did it myself as well but mine was lighter you would not think it was possible seeing were Dans boat was and the space he did it in,he got the block and tackles cheap of ebay hes a good lateral thinker,have you worked out how your doing yours, it should be very light and easy being a cat hull,cheers chris.

[stevemid]

have you worked out how your doing yours, it should be very light and easy being a cat hull,cheers chris.

Hi Chris, in addition to turning the hull, I'm now bow-in and need to be stern-in. So the hull needs to come out of the shed. I'm going to jack the hull up, cut the build jig out, put a trailer under it and tow it clear of the shed. Then I'm going to lower the transom down to the ground. Using ropes, I'll lift the bow and flip it end for end. Then, back on the trailer and reverse it back into the shed. That's the plan, version 14 and counting

[Rip it up]

Any updates?

[stevemid]

Greetings from dust city,
My last update was about a month ago when I finished constructing the motor wells and modifying the duck board to get rid of the curved sections. For the last 4 weeks I’ve been fairing the hulls prior to turning. I've included some pictures from when I smeared on the first coat of bog; that was 17 June. I've since sanded that off and re-applied and sanded that off as well.

Then I've gone over every internal and external corner (joins) and fill them with bog before sanding again to make ‘em smooth. Just when I'm ready to call it "fair" I see something else that stands out like dogs balls. One example is the bottoms of the hulls. These sections start out pretty much horizontal at the stern and twist to nearly vertical at the bow. This leaves a concave curve in the panel which to my eye looks very good. Should this be filled in to make a perfect triangle? Any way I've been farting around with this and similar issues - smearing it on and sanding it off, (wipe on wipe off.)

I finally called Craig Schionning (the designer) and got him to come down day after tomorrow for a Quality Control inspection. Then, I'll at least have a data point to decide how much longer to keep sanding.


This process doesn't really lend itself to updates as the boat looks the same now as it did 3 weeks ago (after multiple iterations). I'm really looking forward to "making progress" again. But I'll tell you one thing, I'm sure going to fair as I go on the remainder of the boat. I need to see progress to keep me going.

Steve

[The Woo]

Stay strong Steve! I feel your pain on the fairing front, our project has involved LOTS of it, inside and out. (see below)

Re the concave underwater sections, I'd be inclined to leave them concave rather than triangulate them. More lift will be gained from the concave style. No doubt the designer will give you the definative answer though.
At least it's only dust mate, not much fibreglass (I find the old fibreglass dust itches more than the new stuff) haha

[Rip it up]

Fairing days mean boardshorts and singlets not tyrex suits and baby powder. Give me a torture board any day. Keep your head up, the interior fabrication see's major changes daily.

[stevemid]

Rip it up, Woo
Thanks for the encouragement. Didn't realise my dobber sounded quite that down. Amazing how much got done in the last few days on the advent of an inspection!
Steve

[Swanie1975]

what grit are you using at the moment for fairing steve? if you get to p80 - 120 you can a spray a light mist of prepsol over the area and it will give you a better reflection and you will be able to see how your panels are shaping up( until it dries off). otherwise you can use a guide coat dusted over the area to be sanded and this will show up the highs/lows in the bog like night and day. at work we use a dry black powder for this but a black spraycan works just as well.

cheers ryan

[stevemid]

Swanie1975
I'm using 40 followed by 80. I saw the powder being used in a youtube video (getting on-line tuition on fairing) where they were blocking a door panel. What's it called? I've got some cheap black acrylic spray paint but I wonder about creating adhesion problems with that. The powder seems to have its advantages. I also bought one of the adjustable flexibility sander kits which I also saw on youtube as they looked the goods. Various sizes up to 27"

Where's a good source (store or on-line) for buying autobody stuff?

[chris69]

hi there Steve haveing fun i see you can use some string line chalk blue stuff worked ok and with the black acylic well if you can still see it you have more work to get it out as you no, when i got down to the small hollows i used a niko pen to mark out any spots and sanded the hollows to get the marker out of it,i just changed colours after each fill and sand so you dont miss any, look good yes i toltaly agree with you when you start fairng it takes a bit to get it right but thats a very important bit of the boat building and when your happy with it,its done and time for the highbuild primer what system are you painting with,cheers chris.