On my largest hulls I still use only 1/4 inch birch ply keel/bulkhead with one mm ply sub-decking.

The wood size is an indication to help you build a model and I doubt you would need to double the sizes for the construction. If you are working to scale than the deck plank widths will be bigger but no thicker. I prefer to cover my deck with liteply sheets then add planking on top. If you build the model too heavy it will not sail as well as one constructed out of lighter material. It is a model and does not need to be built like a "tank" just strong enough to take the odd knock.
dave976

Hi
The current plan has timber sizes shown as 3/16in,5/16, 1/4in, etc so presumably when the plan is enlarged I would need timber double the size. Also the planking is shown as 3/32 x 3/8 spruce again presumably I would need to double this size??

You could but the outlines would also increase in size. There is a free program Poste Erazer that will enlarge then print on sheets of A4 paper. I have used many times and much cheaper than going to a print shop and asking them to enlarge and print.
dave976

If more then one sheet double check measurement to ensure correct uniformity.
Austing👍

from an a4 print
1. load into ms paint
2. go into print set up
3. print at 2pages x 2pages or what size you require
4. trim and stick together

If you use a photocopier to do this there will be peripheral distortions because of the lens characteristics --- ask if there are any other systems that enlarge without said distortions!

I’m not sure where you live, but here in the states FEDEX stores have a ‘do it yourself’ large format copier that I used to use, that was very reasonable in price.

I have also used an office copier to print enlarged 8x 17 copies and then tape them up.

Many Thanks

I know a guy locally who can do this and will see how much it cost!!!!

Yes. All dimensions would be doubled, so there should be no problem with parts, as well as the plan, profile and cross-sectional views.