The deck on this one cracked where the sailor's heel rests. Opened up it and dug out the crushed foam. It's an odd shape. I guess I'd like to glue styro in but I don't know where to get good styro in Brisbane and the odd shape might make it hard to fit closely. Any suggestions? Can expanding foam be used to fill this space? What type?

I have divinycel and carbon to go over the top.

Shifu, is that your tribute to the diggers on Anzac Day?
or to Dale from the castle? "Dale dug a hole."

On a serious note, lest we forget.

Get an off cut from a board shaper.
Glue it in with epoxy and sand back to shape

Too hard to cut a bit n fill. And weaker, will be a bit of a gap around the sides. If u fill that gap it will be heavy (ish) and risk of heat melting stuff. Mayyybe

Use a 2 pack polyurethane like ERA GP330 which is aussie made. $30 and lasts many repairs if you keep it well sealed and in fridge..
Best thing about a liquid pour foam is it fills all the tiny cracks in the styro so it glues it all together and fills the hole. About the same density as the styro when set.

If you use the bit of deck you cut out, in a plastic bag to stop it sticking, as a cap over the expanding foam you will end up with the top surface being really close to the correct level (less sanding) and induce a bit more penetration into the core.

Also does not get hot like epoxy so u can't bugger it, and it sets in a few mins. I've filled and then been ready to laminate the d'cell in 15mins all up. Not that I do, I'd rather give the PU foam time to be proper goodly set.

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Sparky said..
Shifu, is that your tribute to the diggers on Anzac Day?
or to Dale from the castle? "Dale dug a hole."

On a serious note, lest we forget.

I've been working on board repairs all day. Nice weather for it. Good on ya Diggers!

You need more tools .
know any ?
the foam in a can is pretty stable stuff and sands Ezzy.
i would also go with that ..the board looks good .

how did your get such a big whole in it .?

100% with Mark here, in the old days I would have made that hole square so I could fit a block of styrene in, but urethane in a can is much easier. as Mark says if you cap the hole off the foam will be more dense and closer to the right shape.

Tilt the board first so the hole is down, that way you can get the liquid into the centre of the hole and it will expand more evenly.

^^ but the cheap single pack stuff tends to rise unevenly so it can gave big voids, capping the area is necessary to ensure decent density and uniformity . The 2 pack stuff is wayyyy more consistent and $30 = 30 repairs whereas the Bunnings cans = $10 one repair.

BTW just out of interest I have been meaning to mention one that I thought was dodgy but I have played with it and it seems pretty good:
The "Tarzan's Grip" that is actually a polyurethane glue............ yellow liquid and sets just like a rock hard brown / yellow PU foam....NOT the clear one that stinks of solvents.
It is a glue and it expands a smidge....it can glue polystyrene and as with all single pack polyurethanes it sets by absorbing ambient moisture (which most board repairs have - damp styro!! )
So for an area of styro that is just cracked, forcing this stuff in is cheap easy and works great!! then do the d'cell and glassing as normal. Will post proper later.... and not suggesting this huge area should be filled with Tarzan's Grip glue.

Sorry,should have said "cans", agreed the single can stuff is crap.

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Mark _australia said..
Too hard to cut a bit n fill. And weaker, will be a bit of a gap around the sides. If u fill that gap it will be heavy (ish) and risk of heat melting stuff. Mayyybe

Use a 2 pack polyurethane like ERA GP330 which is aussie made. $30 and lasts many repairs if you keep it well sealed and in fridge..
Best thing about a liquid pour foam is it fills all the tiny cracks in the styro so it glues it all together and fills the hole. About the same density as the styro when set.

If you use the bit of deck you cut out, in a plastic bag to stop it sticking, as a cap over the expanding foam you will end up with the top surface being really close to the correct level (less sanding) and induce a bit more penetration into the core.

Also does not get hot like epoxy so u can't bugger it, and it sets in a few mins. I've filled and then been ready to laminate the d'cell in 15mins all up. Not that I do, I'd rather give the PU foam time to be proper goodly set.

Is that stuff good for a soft deck? I've used the Bunnings squirt can of insulation foam before and that was cheap and easy, but if that stuff is better ... . Can you squirt it in?

I don't think it would be as it does not expand much so would be hard to know you got it everywhere
But once you have an open core and its only cracked it works great!

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Mark _australia said..
I don't think it would be as it does not expand much so would be hard to know you got it everywhere
But once you have an open core and its only cracked it works great!

we use PU glue (the tarzan stuff is an example) to seal and repair foam rc flying wings. We mix it with water to increase the expansion and lighten the final product. Generally there are threads describing mixing gorilla glue (was at masters) with water to make a foaming gap filling adhesive

I have been able to syringe it - messy filling the syringe

cheers Jeff