Thread: Correcting mistake

More information might be required to answer this.
1/4" is about 6.5 mm so 6mm ply might be loose, however 7mm will be tight.
1/2" is about 12.7mm so again 12mm ply would be loose, however 13mm could be tight.

With imperial plans it is necessary to convert if working in metric but remember common sizes available here will be different to the USA.

Hi Handyjack, thanks for replying -the measurement is 3/4inch which is about 19 mm whereas I have 18mm ply. I'm keen to find a solution because after the box there are several pieces to the whole plan and they have been cut to size (in inches)

I build a lot with ply and have always found it be slightly under the stated size. Most articles state if using eg. 19mm ply, do not machine a 19mm dado - machine to suit. On the other side, you can buy 19mm ply from specialist ply places but many other places only keep 18mm for some reason.
If you have already machined dados, you will have to redo or fill with a full width insert and re machine or use a narrow fill insert. If you have only cut the panels to size, then you maybe able to resize the plans to suit 18mm ply - been there, done that. Would be interesting to see a rough sketch of the item or a copy of the plan to see if this last option is possible.

I've battled for quite a long time with this sort of thing and my works being just not quite right. Either my measuring implements weren't consistent or my technique and tooling not accurate enough to produce quality results. Over time I've upgraded my tooling a little and learned a lot from my mistakes. 2 things i now do regularly that have helped immensely are: rely less on measurements and more on marking and cutting to fit (where applicable of course) and
Building a dado jig for the router. Creates perfect width trenches every time, regardless of variance in the timber from its spec or my miscalculations along the way.

I dont know if that's all that useful to you now but i rarely cut all pieces to measurements from the outset anymore.

Not ideal and depends on how many bits you need to do and, yes, there is sanding to fit required. Also if the ply to trench are highly visible then I would not use it.

Take a strip of (old flannel PJs are good). Make it quite wet and lay the strip along the edge to be fitted, take an iron (old electric one not SWMBO's best one), set to steam setting as hot as it will go and iron the strip of wet flannel. The heat, moisture and steam will cause the strip and edge to swell slightly as well as raising the fibres on the surface which will need to be sanded smooth.

If done carefully the edge should not delaminate or curve/warp unless you do it too many times.

As I said not ideal and if you have a heap to do then the other alternatives stated above are a much better idea.

Just a thought to get you out of trouble.

Hi All, have had some helpful replies(of course). So the plan now is to redraw the plans. What scale do the "woodies" use. Have read about the working rod but I'm interested in paper plan. What are the ratios or to what scale do people use. This is for a cabinet which is 660mm wide and 1600mm height. Thanks again to all. Cintamate

1:5 or 1:10 is good . At that size I would use the 1:5 though.

Rob

I would use any suitable scale where I could fit the whole drawing on the same sheet of paper.
1:10 is an easy one to draw so your drawing is 160mm high and 66mm wide. That might be a bit small on A4 paper but if you double the size 1:5 it would be 320mm high and 132mm wide which is just a bit too big for an A4 sheet.

Originally Posted by cintamate

Hi, I'm making a box from a plan. I am in Australia and am using USA plan. I have measured the material and cut it in inches but the ply was in mm and therefore not as thick. Will this impact on the final measurement of the overall box and if so how do I compensate for this?
Cintamate

Originally Posted by cintamate

This is for a cabinet which is 660mm wide and 1600mm height.

I'd need to see the plan, but, based on the outside dimensions of your box, I don't think anyone will be able to tell that instead of being 660 x 1600, the box is actually 658 x 1598

you may just need to shave 1 or 2mm off some internal dividers