Thread: RE: Using the Metric System in USA - getting tape measures and others

Howdy.

The most common size for plywood around the world is 2440 x 1220.

That is what they sell it as.

Being 3mm out is not going to be a problem. If you notice all the dimensions for the side panels are from one end of the ply. The other end of the ply never comes into the marking out. The sides also finish before the other end.

The only piece that goes the full length of the plywood is the bottom and it is trimmed off after fitting. Do it neatly as you need the offcut - even if yours may end up being 1/8" (or 3mm shorter).

In other words the way the plan was set up was to allow for exactly the problem that you have run into.

If by some chance I have started any measurements for the sides from the other end - please mention it here and I will fix it.

Best wishes
Michael

Originally Posted by Boatmik

Howdy.
The only piece that goes the full length of the plywood is the bottom and it is trimmed off after fitting. Do it neatly as you need the offcut - even if yours may end up being 1/8" (or 3mm shorter).

Originally Posted by m2c1Iw

The other thing I have found is for the bottom try and leave as much length as possible when cutting the web pieces, I was about 10mm short.

Michael I have noticed previous reference to the bottom being a little too short after allowing for the #1 frame web as I have experienced and wonder if the web pieces could stand being reduced 10mm in width without affecting strength? I cut the pieces prior to fitting the bottom using the dimensions quoted in the frame layout pages. Suppose I should have followed designers intructions and fitted the bottom first.

Mike

Originally Posted by m2c1Iw

Suppose I should have followed designers intructions and fitted the bottom first.

Don't do that, the designers might start getting delusional and thinking they know what they're doing

Richard

Howdy Mike.

The offcut from the bottom is used to make the centreboard case front web (and a couple of other little bits if I remember right.

If the bottom is dry fitted, marked and cut with a little bit of excess all will be OK.

The web for the front of the centrecase doesn't really need to be any specific width. If it is 5, 10, or 20mm narrower it doesn't matter - there just needs to be something there.

So dry fit the bottom first - mark and cut for a perfect fit.

As Daddles says ... the plans have been worked out to provide a number of failsafes of this type. I don't promise they are perfect - but I am used to nutting out on the way to minimise the risks of these types of problems.

For example there is no way of guaranteeing that everyone's bottoms will end up the same length - that is why I don't give a length at all - instead a procedure for working out the correct length using a minimum number of steps. It also gets the builder used to the process and provides guide holes for the final run.

There is a huge amount of this sort of protection in the plan. Again it is impossible to cover all the bases but I think they go pretty close.



Unusually I have built or substantially built 5 of them now.

Best wishes
Michael

Originally Posted by Boatmik

If you notice all the dimensions for the side panels are from one end of the ply. The other end of the ply never comes into the marking out. The sides also finish before the other end.

If by some chance I have started any measurements for the sides from the other end - please mention it here and I will fix it.

I suspect my problem is that I am trying to draw out both side panels. I drew out one side starting from the stern and going left to right across the plywood. To draw the other side panel, this time working from right to left, I can't use the same grid lines because the first line is 302mm from the right edge of the ply instead of 305.

As the plans clearly state, it is ok to measure out one side and then copy the other. I bet doing that will help the two sides to match up better anyway. It is probably better to have the sides the same no mater what the shape.

I'm really looking forward to working with the metric system. This is so much easier!

Thanks!
Andy

Yep - that is the best possible way. You can set it the copy using the measurements of the tips of the panel from the ends and middle of the ply.

As your sheet sounds like it is 1/8" shorter this means that the duplicate will be moved 1/8" to fit OK.

When you start using the duplicates remember that they have to be laid out symmetrically to work out where the framing goes.



As you can see here - all the bits are laid out symmetrically.

One interesting note is that the blue tape is where our plywood broke. I mean broke with hand pressure. The sides and decks were all of that ply which was cheap.

However the boats were quite strong enough showing that with this glued type construction that loads are very distributed. Probably the epoxy coating is helping prevent water getting into to voids too.

However for the bottom of the boat the original plywood was not quite strong enough - so we now recommend 6mm (1/4") for that panel only. The plans only give you the 6mm option for the bottom.

We are very happy with the performance of the thinner slightly crappy ply for everything else - but if you have a bit of extra money then better ply and epoxy is a great investment in the longevity of the boat.

Michael Storer

It looks good. If I was doing it, I would hide it.

Well here it be. What ya think? Is it good to go?

[ame="http://www.youtube.com/watch?v=_4RJAeP7pDI"]YouTube - Canoe Paddling - Canadian Style[/ame]

Heres a vid for fun. Keith

Howdy Keith,

Cheers for the Vid.

It is a bit hard for Australians to realise what heights canoeing as an artform has achieved in a few short centuries in Nth America.

Thankyou hugely as the video is both entertaining and has some useful material as well.

Anyway ... to go back to what coogzilla is building ... it is one of these.



The simplest of box boats. The PDRacer.

If you look carefully you can see where I faked the photo. It was vertical and narrow and I had to make it square for publication. So the left and right sides are copied from elsewhere on the picture.

MIK

Where do people typically get 19mm x 19mm - 3/4 x 3/4 timber in the US? The box stores like Lowes & Home Depot do not have anything close. Or do is it best to just rip something else to the right size on a table saw (which I don't have)?

Thanks!
Andy

Andy

I'm not in the USA, but the better timberyards here in Oz (not Bunnings - seems to be our equivalent of Home Depot) will rip a board if you want (usually no charge). Bunnies wil cross cut, but rarely rip. Ask the salesman nicely and you may be surprised!

If you buy a 30 or 15 cm (12" or 6") board of 19mm (3/4") you can usually rip it yourself if you are cureful using a portable circular saw. As far as I am concerned the major issue here is ensuring that the board is supported at enough points not to sag and then vibrate - you don't want to know what starts to happen then!!!

You'd be amazed what you can do with the really cheap table saws mate. Then there's the Triton (which I think you lot get). While having a good table saw improves the job, there's not a lot you 'need' it for. Mind you, if you have one you'll find yourself doing all sorts of stuff you hadn't anticipated - like ripping down the plywood sheet to make my steam box recently, knocking 5mm off the edge of the boards I was trying to steam, making a small part about a foot long for a wheelchair adaption my dad was doing. I've got a Triton and started with a borrowed circular saw but recently bought a larger saw. Paying lumber yards to rip and plane the timber is very expensive and very restrictive, but it does mean you don't have to buy a saw. I did that until I realised it was cheaper to buy something to have here at home.

A mate was in the same position as me but could afford to buy a good quality table saw ... almost. The money was there but he wasn't sure if he'd use it. So he bought a really cheap table saw for less than $100, just to see how long it'd be before he'd get sick of it and buy the real thing. Well that was 5 years ago and he's still using it. The cheap fence was tossed early on and he made up something that's a beast to use but which is at least stable.

My experience with Redback was that I'd spent enough paying the lumber yard to pay for the Triton and had none of the flexibility. On that basis, with most boats, you can justify a saw just for that one job. Mind you, then you have to get a thicknesser which makes the economics really dodgy, but you'd be amazed what you can do with hand planes.

Richard

It is moving a bit away from tape measures, but with a portable circular you can make it a lot safer by putting it on a sacrificial layer of chipboard on the floor or a good table or a Midge style table frame. Fully supported. On the floor with sacrificial chipboard under is the easiest way to cut out ply panels if you really want to use a circular saw - adjust the depth of cut to go into the chipboard a few millimetres.

MIK

Originally Posted by Boatmik

It is moving a bit away from tape measures, but with a portable circular you can make it a lot safer by putting it on a sacrificial layer of chipboard on the floor or a good table or a Midge style table frame. Fully supported. On the floor with sacrificial chipboard under is the easiest way to cut out ply panels if you really want to use a circular saw - adjust the depth of cut to go into the chipboard a few millimetres.

MIK

Yup, works a treat that does

Richard