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Addem

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Posts posted by Addem

    Round North Island, 2 Handed ---2017

    in ShortTalk

    Posted

    A sad state of affairs that, but demonstrates exactly why people like me don't buy what was once the best sailing magazine in the country.

     

    Some of the best reading around is the stories on sites like this one, it provides my fix. Or maybe I need to get out more.

    Apart from 84 pages on Trump.

    Tongan Trimaran for outer islands

    in MarineTalk

    Posted

    Easy way in windows to make it smaller is to open it in the picture viewer and click on 'email'. It will ask how big you want it. Choose large and it'll be just perfect. It'll open an email with it attached. Just copy or save that to desktop and you can upload it from there.

    Vaccum Pump Kiwi No 8 style

    in TechTalk

    Posted

    You got that right. Bazzathemammoth can source me a switch for $140 which I declined as it sort of defeats the purpose. I'm gonna try a regulator as you suggest. I'll work one out and we'll compare notes.

     

    My fall back is a spring loaded syringe and micro switch.

    Vaccum Pump Kiwi No 8 style

    in TechTalk

    Posted

    Thanks for the idea Wheels. My guess was that it would be better for the pump to be turned off when down to vacuum and turned back on when more vac was needed. With a regulator the pump would run continuously, would it not? Do you think the pump is ok if it is running for 5 hours or so while the resin goes off?

     

    It be real helpful to know what amount of vacuum is actually needed. KM?

    Vaccum Pump Kiwi No 8 style

    in TechTalk

    Posted

    WARNING:  This post has lots of "rough as" stuff in it.

     

    I was inspired by the Vacuum Bagging No8 Kiwi style post by Guest_* a while back and, having a spare weekend, decided to see follow suit and make a vacuum pump from and old mini bar fridge I had laying around.

     

     

    I spent a bit of time trawling youtube and found that this was going to be easy as.  In point of fact, I discovered that the more rough I was prepared to be, the easier it has turned out.

     

     

    In double point of fact, this turned out to be so absurdly simple, I did it all with only three tools (my whole toolkit was 120nm away on the boat, which was drifting around with my mates in the Chains and Anchors 150 thingy - so I really had to use my imagination):  A stanley knife blade and pair of long nose pliers and a hacksaw was all I could come up with. I also found an old syringe (not sure why I had one of those, but it was useful).

     

     

    So, I did this on Saturday morning  - took about 3 hours, and a lot of that was checking stuff on Youtube.  I've run a few trials and it seems to work but with the limited tools at my disposal I can’t say how much suck or CFM or any other technical stuff there is.  I tried taking measurements with the hacksaw but couldn't get it to read properly.  And the pliers are too rusty to be helpful (I know that one shouldn’t blame ones tools, but there you have it).  Because I had to take the in-laws (the pain) out in the boat (the pleasure) this afternoon (it having just returned from AK) and didn't want to feel the whole day would be a waste, I set up some tests further before I left.  (disclaimer so that you don’t feel you have to point out the flaws in my technique - I only had a few spare hours and wanted to see how it would work in real life so made a few quick moulds/shapes to suck on to).  Seems to have worked fine on these small things.  Below is a detailed explanation of what I did.

     

     

    STEP ONE = MAKING THE PUMP

    First thing was to watch the best friggin youtube on friggin vacuum friggin frigs:  www.youtube.com/watch?v=XV5Wj2iURSE&t=173s.  (This is really worth watching- it’s friggin brilliant).

     

     

     
    (The finished product)

     

    I took to the two copper lines with a hacksaw.  I didn’t really know about what sort of refrigerant was in them (and I really shouldn’t be posting this on here in case you all think I just dumped a whole heap of CFC’s into the atmosphere – I hope not, and if I did, it is only a small fridge).  All that came out was a heap of clear oil, which poured all over the drive.  Gave that a quick clean up before the lady of the house spotted it.

     

     

    Then I undid (with the pliers) the retaining plate for the compressor to separate it from the carcass.  I decided to keep everything attached to the retaining plate as it serves as a base for it and if I decide to keep it I can now easily mount it on a piece of MDF for a stand.

     

     

    I was unsure what to do about the thermostat, so ran the first few tests with it still all attached to the fridge carcass.

     

     

    First test was to check it actually did suck.  I had some old tubing and a few valves from a fish tank set up and they slipped straight on the vacuum side of the compressor.  I plugged it in and, hey presto, we had suction.  I attached a coke bottle and it made a pretty good job of imploding that, so we were good to go.

     

     

    I was worried about the oil that ended up on the driveway and Youtube again showed me that the oil was from the lubricant bath that the whole unit sits in (this is a reason the compressors are located inside a sealed canister – one doesn’t want oil dribbling all over the lounge when moving the thing around).  So, the loss of oil meant that I was probably running it dry and serious damage was imminent.  I did some quick maths (Pie r2 x approximate height of where I thought the oil level should be) – another good youtube link for this: www.youtube.com/watch?v=3n8Kby6kgXc&t=26s.

     

     

    I chopped off the end of the oil feed tube and topped it up with about 200ml of 5w-40 synthetic oil.  Restarted and - no suction.  Seems that the other reason the compressors are in a sealed unit is that they are designed to be in a closed system.  I sealed up the oil filler tube with good old blue tack and was back in business again.

     

     

     
    (blue Tac pressure proof oil cap)

     

    I’m not good with electrickery things but, after looking for 10 minutes at the ludicrously simple wiring diagram stuck to the side of the fridge and recalling the basic science I learnt at school, I finally figured out that the thermostat circuit was a simple binary set up (on/off) with a ground for good measure.  So I just chopped the wires off and joined the black and yellow one together and left the yellow/green alone.  Bugger me, but it still worked.  Because I don’t trust myself, I decided I’d put that whole circuit inside a plastic container so I couldn’t do anything silly, like dangle my hair in the live bits.  I’ll have to sort out later how to make this into an on/off switch (see below).

     

     

     

    (nasty electric bits safely tucked away)

     

    And there after not very long, was my vacuum pump.

     

     

    STEP 2 = TESTING.

     

    To test it I used the old carcass as it has a very smooth surface.  With some old plastic bags, blue tack and masking tape, I set up a bag and put various objects inside to see how it would all suck down. 

     

     

    Two issues arose:  One – it was impossible to get masking tape and blue tack to seal, so while it sucked down OK, it couldn’t hold it.  Second was that it was obvious such a small amount of pipe and volume inside the bag, the pump was in binary mode – full vacuum in seconds and then nothing.  I needed a reservoir.

     

     

    My simple reservoir is a medium sized jam jar with two holes drilled in the top (did I mention I still had a drill?) and the pipes fed though and sealed with silicone.  The thing works somewhat perfectly.  Because of the problem with the masking tape leaks and the rudimentary nature of the setup I didn’t have high hopes for it holding a true vacuum, but it could hold it for a few minutes before needing a recharge.  I used the syringe to test the ability of the reservoir to hold the vacuum and got it to about 10 minutes.

     

     

     
    (soon to be patented jam jar reservoir)

     

    I figure that what I really need is an adjustable vacuum switch. I reckon I can make one using the syringe with a spring inside it and a micro switch from Jaycar.  Or source one from somewhere.  I have googled the letters off the laptop and haven’t been able to find one.  Does anyone have any ideas?

     

     

    STEP THREE – TESTING IN EARNEST (sort of)

     

    As I said, I only had a few hours available this morning before torture by In-Laws, so I decided to do a simple suck down on a flat object.  I cut out a square from some cardboard, trimmed up 8 pieces of glass mat and set up the MkII “bag on a fridge”.  This time I laid a trail of silicone and put my extract tube through it.  Bingo – works a treat.  To save time (and not having any release agent on hand) I spread some glad wrap on the fridge first and made sure it was air bubble and wrinkle free.  Talk about easy, I’ll definitely do this again.  Rather than lay it up I wanted to try a hybrid infusion, so I mixed up some epoxy and poured it onto the stack of fibre mat (8 ply).  I laid my plastic sheet (an old shopping bag) and no peel ply because I wanted to see what would happen, and turned it all on.  It all sucked down beautifully and the silicon provided a total air tight seal.  The resin infused itself throughout the mat and the surplus made its way to the extract pipe.

     

     

     
    (the flat shape suck down)
     
    Due to the lack of a switch I got a rotary timer switch and set it to turn on and off in 15 minute cycles.  Seemed to do the job.

     

    As I was watching, I got ambitious and thought, “why not try an infusion on a 3 dimensional shape?”.

     

     

    So, with some old foam, the trusty Stanley knife blade and lots of blood from the bloody thing, I fashioned a shape sort of like a door handle.  As the hour of doom was nearing I grabbed a glad bag, cut a corner off and siliconed in a piece of pipe to act as the draw for the epoxy, put a nick in the bag near the opening and siliconed in a second pipe for the extract. 

     

     

    Then I got cunning and thought to myself “Self, why not do both tests at the same time?”  So, I got a T junction from the fish tank bits and teed off a pipe to the new bag.  I tested that it held the vacuum, quickly wrapped the new shape in glass tape, a bit of old spinnaker cloth for the peel ply (as suggested in the previous post), wrapped that in some weed mat (also suggested previously), mixed up some epoxy, stuck the pipes in, turned on the pump and…. It worked!  Somewhat.  I was watching the progress of the epoxy up the matting, when it started to stop.  I wondered if I had lost suction, but everything was still sucked down, the reservoir was still sealed and everything was normal.  Then I felt the epoxy jar and it was hot, hot, hot.  Ah.  I used the fast setting resin (West 205) and may have been overzealous in the mixing.  Still, the conclusion was that it will work, with a little more finesse and perhaps not doing two objects simultaneously.

     

     

     

    (More complex and not so successful)

     

     

    (the finished products)

     

    NEXT

    Things I have learned. 

     

     

    8 layers of fibreglass matting is only about 3mm thick.  WOW.  How many layers of carbon go into a mast, one wonders?

     

     

    I really need an adjustable switching mechanism.

     

     

    I think a pressure cooker will make a good reservoir and I can mount proper pressure fittings into the lid.

     

     

    The glad snaplock bag seems to really work (but needs a wipe of silicon on the snap seal to give a good closure.

     

     

    Gladwrap makes a brilliant release surface.

     

     

    All up I spent about 5 hours on this, used a few dollars of silicone, a cup of good quality oil, some fish tank bits that might have cost $20.  All up – a useable vac pump for under $30.

     

     

    Now, I know where I get a larger compressor from a deep freeze unit….

     

     

    And no In- laws were harmed in the making of this post.

     

     
    (Blue tack pressure proof oil cap)
    • Upvote 4

    Extreme sailing series GC32 foiling cats

    in RaceTalk

    Posted

    I notice that there hasn't been any comment on this racing series. Does anyone on Crew follow this? I don't really follow it but enjoy watching when I get time (actually I enjoy watching any yachting except - no, can't think of anything I wouldn't enjoy watching). It's streamed on you tube: https://www.youtube.com/user/ExtremeSailingSeries

     

    There are two NZ teams this year and I hadn't heard anything about them. Plus two of the other teams are skippered by Kiwi's - Adam Minoprio And Phil Robertson.

     

    I suppose the only place this sort of thing would get announced is Yachting NZ newsletter but I gave up reading it A long time ago.

     

    Does anyone know anyhthjng about the two NZ teams?

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