Hi, I've bought a copy of the Alternative IOM from BG and am looking at the alternatives for construction. The plug method looks attractive from a number of aspects, but obviously requires a quantity of 100mm styrofoam sheet. So my question is - can anyone recommend a source for this please? I'm confused by my on-line searches, which often return results for polystyrene sheets, but these seem to be made from a granular material - a bit like the cheap protection blocks used for packing electrical products. As far as I understand styrofoam (the blue stuff shown in Brad's video on how to make a plug) is more like a foam and therefore will be easier to shape. I have to say it looks as if it might be quite expensive and shipping might be an issue as it's easily damaged.

Any advice would be really welcome. Many thanks. (BTW I haven't ruled out balsa/cedar strips yet!).

I got mine from Amazon. No longer made blue, it’s now black.

Many thanks Nigel, I had a search on Amazon just now for styrofoam sheets (and blocks and board). But my search didn’t return anything useful. Plenty of 5mm or 2.5cm stuff, but nothing remotely like the product needed. I must be getting something wrong. Any thoughts on how I can improve the search terms? Once again, many thanks for your help.

Hi Martin,

Like you, I searched hard to find XPS foam in any size at a reasonable cost. It is true that it is now grey/black and I think it is not quite as good for our purpose as the old blue stuff. Unfortunately that seems to have disappeared  off the planet!

Finding a source that will supply less than a minimum of 2 square miles is also near impossible, unless you buy the exorbitant  model sized pieces.

I found this on E bay:   gb-range and they offer delivery of decent sheets with no minimum. I have just checked and, unfortunately, they are out of stock of 20mm but do have 10 & 30 available.    I have used loads now on prototype hulls and is ok.  

Alternative is a great build:  hope you keep us informed of progress.

Richard

Ps Martin,

See the IOM forum on "Alternative build" for info on mine.

The foam approach takes loads of practise, unless you have experience of fairing surfboards or other such things. The attraction is that you end up with a mould. However the whole caboodle becomes scrap if not perfect. It is also messy and time consuming. Planking is simple and easy to start again if not happy. Just have to remember the three rules. 1. Keep the weight down. 2. Avoid any, no matter how small, excess weight.  3. both of the previous.

Richard

Try here https://www.easycomposites.co.uk/low-density-polyurethane-foam-block

Or here https://bluefoam.co.uk/

Hi Richard and Steve, Many thanks for your advice. I'll check out the links, but also give careful thought about whether to use wood strip construction (it does seem a little quicker and I guess can also result in creating a plug). It's a bit ironic that for about the cost of a quantity of foam for one hull I could buy a budget/second-hand scroll saw - which I think would be invaluable for a wood strip build (and can be used again and again).