Closed cell foam for laminating

C08

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I want to make some skegs for my cat and plan to use 18mm marine ply epoxied together and finished with a couple of layers of cloth/epoxy. I have done a fair bit of laminating and repair work with epoxy and polyester so I am comfortable with the construction but I have never used any foam. I will have a gap between the inner and outer ply in the skegs of about 20mm tapering down to nothing. I could just leave it hollow but that is probably not a sound idea. What am I best using, does it cut easily and where from in uk. and Is there any easily available foam I could use which is also cheap compared to the price of exotic boat building products?
thanks as always.
 

geem

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Why not use a solid foam core and glass this in multiple layers cloth/epoxy to create strength. My experience of ply for this application is that you add a lot of weight and it will get water in. At least if you use something like Airex core the water will have little detrimental effect. Your cat wont benefit from wet plywood and the weight
 

C08

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Why not use a solid foam core and glass this in multiple layers cloth/epoxy to create strength. My experience of ply for this application is that you add a lot of weight and it will get water in. At least if you use something like Airex core the water will have little detrimental effect. Your cat wont benefit from wet plywood and the weight

Thanks for suggestion but your suggestion although lighter would I think more difficult to get a flat and desired shape than starting with flat ply to laminate cloth to.
I also have enough ply, cloth and epoxy to do the job but if I used a full foam core I would need more epoxy to do the job.
 

TQA

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I would use urethane foam. Finer cells and sands nicely. Often used for insulation in buildings and comes in colors usually blue or pink but I have had green.

Sheffield Insulation is a supplier but they have a minimum order. By the sounds of it you only need an offcut. Maybe a bit of dumpster diving at a building site.
 

lpdsn

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and Is there any easily available foam I could use which is also cheap compared to the price of exotic boat building products?

Check the spec of the foam you use. Some of the 'exotic boat building' stuff won't absorb water even at significant pressures.
 

Tranona

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You can get expanding closed cell foam specifically for this application. I got mine from Blue Gee, but any GRP or epoxy supplier will have it.
 

geem

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Thanks for suggestion but your suggestion although lighter would I think more difficult to get a flat and desired shape than starting with flat ply to laminate cloth to.
I also have enough ply, cloth and epoxy to do the job but if I used a full foam core I would need more epoxy to do the job.
if you laminate your foam together into a big block you can shape it with a sander. This is how surfboards are made. it is not so hard to do. You are only really using the foam as a former for the epoxy so yes you probably would need more glass and epoxy. From my experience skegs always get water into them as the fixings for rudders always cause water ingress.
 

STATUE

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Go and see Andy Miller of 'boatworkstoday.com' in Wisconsin.

He is the best - talks our language and no bull - and not product dependent.

https://www.youtube.com/watch?v=i9hfpOCnzEs

I am product depedent because I was going to rebuild my rudder on my Frances 26, but insurance, 'SAGA' came and rescued me and paid for it to be done.

However, I have unopened in my garage a 16 LB (the yanks talk in old weights !) kit of US Composites closed cell urethane foam - see how Andy uses it .

I ordered it last year and have kept it in good conditions in my garage and is unopened.

To get it across the pond the total charge inc. the product was $113.50 or £76.70.

Including postage, I am selling it for £38.
 

ronsurf

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Get a surfboard blank, available in all sorts of lengths and thicknesses, from about £30 if memory serves well. These are polyurethane and can be shaped with any wood working tools. Power plane and sanding screen most effective. Very easy to work with.
 

prof pat pending

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I want to make some skegs for my cat and plan to use 18mm marine ply epoxied together and finished with a couple of layers of cloth/epoxy. I have done a fair bit of laminating and repair work with epoxy and polyester so I am comfortable with the construction but I have never used any foam. I will have a gap between the inner and outer ply in the skegs of about 20mm tapering down to nothing. I could just leave it hollow but that is probably not a sound idea. What am I best using, does it cut easily and where from in uk. and Is there any easily available foam I could use which is also cheap compared to the price of exotic boat building products?
thanks as always.

Try this

http://www.easycomposites.co.uk/Category/Core-Materials/Closed-Cell-Foam-and-3DCore.aspx
 

C08

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Go and see Andy Miller of 'boatworkstoday.com' in Wisconsin.

He is the best - talks our language and no bull - and not product dependent.

https://www.youtube.com/watch?v=i9hfpOCnzEs

I am product depedent because I was going to rebuild my rudder on my Frances 26, but insurance, 'SAGA' came and rescued me and paid for it to be done.

However, I have unopened in my garage a 16 LB (the yanks talk in old weights !) kit of US Composites closed cell urethane foam - see how Andy uses it .

I ordered it last year and have kept it in good conditions in my garage and is unopened.

To get it across the pond the total charge inc. the product was $113.50 or £76.70.

Including postage, I am selling it for £38.


Thanks for your offer but I only need a small amount.
 
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