Yes, cos no-one can afford to use it in production boats! Good choice for your prototype tho'. Don't bother with routing long strips, do vertical wider strips and glue them with PU adhesive [Gorilla grip]
the best thing about corecell with regards to this project is how well it takes to heat forming. Either buy yourself an old domestic oven from Craig's list or make a heating box ( for small projects these are often made with timber, fibreglass insulation and a couple of heat guns) and you will able to shape wide transverse runs of foam and do minimum fairing or gluing.
Corecell is probably the best foam on the market, however, it is banned in the F18 class, not worthwhile on a boat built with a chopper gun or inferior to nomex for high end builds. As a result we see very little of it in beach cat land.
With quite a few hundred hours invested in a strip-plank project I feel confident when advicing: Stay away from the devils building method if you want a fast build <img src="<>/wink.gif" alt="wink" title="wink" height="15" width="15" />
x 1.5
x 8 foot from one end, it probably wouldn't flex 2 inches on the extreme end. It machines like butter.
Jake, which foam? There are sooo many different types of foam available it can be overwhelming...right now I have 7 different types of extruded polystyrene in my shop, along with Rohacell and Nomex for use as cores in molds. All the polystyrenes act differently and most wouldn't be suitable for a boat building project but they exist!
Quick word on foam. There are several types I used 3/8 Divinycell H80 and H60 on my project a bit cheaper than core-cell and does not need to be heated. I bought full sheets and ripped them to strips then used a router and cut it with a “canoe bit” which has a combo bead and cove blade. There are two main thoughts on foam stripping horizontal or vertical, the farrier guys like the vertical method. It looks like a good method - but did not work with my design. I used the older horizontal method. Gorilla glue worked good to glue the strips together and fares out well.
Am I reading you right? You can sand gorilla glue to shape?
Pete when I glued the strips with epoxy it did not sand at the same rate as the foam and wanted to dish between the glue and foam.
With Gorilla the dried glue it is about the same density as the foam and sands out fare. Rememeber this is a thin line of glue that may come out between the stips.
Okay, thanks.
Here is picture of a sanded hull with a little help.
With Gorilla the dried glue it is about the same density as the foam and sands out fare. Rememeber this is a thin line of glue that may come out between the stips.
Also - if you wet the surfaces before you apply the gorilla glue, the glue will foam as it cures. More water makes it foam more.
BadLat
From my experience there are two ways to do a foam lay-up. For a one-off you can lay the foam on the inside of the forms or on the outside of the forms.
On the inside of the form method it allows you to do your foam lay-up and first glass them remove the hull half from the form and easy access to the outside of the hull. It takes more care in the alignment of the forms on the strong back as it is harder to visualize the same and form of the hull when looking inside of the forms. When planked out with foam you can see the inside of the hull but again you cannot see the outside of the hull and look down the hull for fairness. This method I believe is easier for the one off boat. It easy to attach the foam and for the most part it stays in place although it wants to curl during curing, I found out the hard way.
Foam on the outside of the forms is much more difficult to attach to the form as you working under and inside the form on a narrow hull. Also you must deduct the finished hull dimension from the form size or you will be adding to size of the hull. If this is done during the lofting it will be easier but often the plans are drawn to the finished size - Just something to think about in the early planning stage.
Now if I were just building a plug I think I would just attach the foam to outside of the forms as it much easier to see the fairness as you go along. You can run the screws into the foam and fare over them. The only thing is that you are putting all your eggs in one basket in hopes that not going through a prototype boat your design will be a good one. You are putting time and money in the plug and mold for a untested boat.
Either way good luck with your project it is a lot of work and fun if you like that sort of thing. I yeah I almost forgot to mention it takes up most of your free time also. Bad lat if you would like some more information about what I have learned to do and not do feel free to contact me. I’ve learned much during my endeavourer.
Regards,
The Man Shed
mike thx for the great info. i will save your email as im sure sumthing will come up lol
Feel free to contact me. If you go though my website it goes though a spam filter first I check it every so often.....damn spammers.