Lining out

[Keeping Up]

Also, i would have though it would be more lightly to be the change in moisture content of the wood.

- Rather then the diffrences in the thermal expansion coefficients of the steel/wood.

Daniel

Ours still moves quite a lot with temperature differences - you can get a 5mm gap suddenly appear at the edge of a cupboard for example - and after 15 years the wood is pretty well dried out by now.

 

Once we had a heavy frost but a very hot sun immediately afterwards. One side of the boat still had frost on it while the other was too hot to touch (trouble with black sides). Every door in the boat was jammed (open or shut) for about 3 hours because the whole boat had twisted so much. We still notice the effect to a lesser extent quite often, we call it the "Chester Effect" after where we were the first time.

 

Get out your tables and calculate how much expansion you get over 70 feet with perhaps 50C temperature change, I think you'll be surprised. And if you recalculate to see how much a radiator would move at the end of a copper heating pipe when it heats up by 100 degrees you'll see why the system creaks so much as it warms up.

 

Allan

[DHutch]

Get out your tables and calculate how much expansion you get over 70 feet with perhaps 50C temperature change, I think you'll be surprised.

We havnt covered that yet, but a quite rummage thought google, i figure for a 70ft lengh of mild steel, and a temperature change of 50c, you would get about half a inch change in lenght.

- So for a 6ft wide roof, you looking at about a few mill.

- Which doesnt eactly explain why our T&G goes from having 2/3mm gap between each plank to well bucked as we change from summer thought to winter.

 

 

Daniel

[Guest]

Coefficient of linear expansion-I have completely forgotten how to work that out now. A boatbuilder we saw was fitting out the lining in ply and I noticed he left a gap between the sheets using a pound coin as a gauge (edge on of course!).

http://www.ac.wwu.edu/~vawter/PhysicsNet/T...ThermExpan.html

[Arducius]

Bit of a thread dredge but this seems an appropriate place for my question so rather than starting a new thread...

 

I've seen at least one person on this here forum use exterior grade OSB (oriented strand board) to line out rather than the more traditional ply. I've also seen people suggest this is not a good idea as it doesn't like getting too wet.

 

We are currently planning to use pine planks to line the roof and cabin sides (250m timber already ordered), and then do under the gunwale in boards (either ply or OSB) with some trim to cover the gaps.

 

OSB would provide a signifcant saving per sheet over ply, but is it likely to fall apart? I know plumbing disasters do happen but we're not talking about having a regular soaking or long periods of remaining wet as we'll be living aboard so hopefully will spot leaks more quickly. I guess there is a lot of damp air about especially on Spring/Autumn mornings and evenings but is this likely to be enough to cause the boards to delaminate?

[james46]

Hi i was looking at any ideas for covering your screws when your lining out a boat with ply was thinking maybe doing a border so the strips cover the screws 

[koukouvagia]

I used a plug cutter.  See https://www.youtube.com/watch?v=ra44s-wtsHY&ab_channel=JonPeters-LongviewWoodworking

 

You can buy the kit here, for example. https://www.screwfix.com/p/erbauer-plug-cutter-countersink-set-4-pieces/6418v#product_additional_details_container

 

 

[james46]

15 minutes ago, koukouvagia said:

I used a plug cutter.  See https://www.youtube.com/watch?v=ra44s-wtsHY&ab_channel=JonPeters-LongviewWoodworking

 

You can buy the kit here, for example. https://www.screwfix.com/p/erbauer-plug-cutter-countersink-set-4-pieces/6418v#product_additional_details_container

 

 

Hi thanks thats a good idea 👌🏻