Trying to get my hands on some Divincell or Herex to mimic the sandwich construction following a big deck crease. Is there a reason this stuff is like hen's teeth, anybody got any suggestions or substitutes? People have suggested a 3mm sheet of balsa or another high density foam. It is a surftech longboard as oppossed sailboard but i ask here as it is similar construction to sailboards.

Based in the illawarra

thanks for the feedback.

be

The Illawarra should have some boatbuilders, go there and ask nicely to buy some offcuts. They all use it for their fibreglass boats.

I managed to scrounge a big bit for free (although the guy who cut it for me told me to stuff it up my jumper so the owner wouldn't see me taking it)

Yep divinycell is hard. It's got high compression strength, which combined with the high tensile strength of glass gives you the amazing properties we strive for.

Balsa would work too.

As usual before attempting something like this, spend a good two hours reading everything on this site:
boardlady.com/


You will save yourself much more than two hours in the long term!

hth

You're right about the board lady!

Corecell is another alternative.
Normal density for a glass sandwich about 80kg/m3

The trouble with balsa is the density varies a bit, but for what you're doing it will be fine.

Make sure you have an overlap of glass on the internal and external layers, otherwise you'll have a weak spot.

try these guys www.jamestowndistributors.com/userportal/search_category.do?categoryName=Wood,%2520Foam,%2520Starboard&categoryId=305&page=GRID they allso have insructional videos so maybe help you out with the other stuff you will need

where are you getting it

B, 24" x 8" is one hell of a crease,
divynicell is only used as a hard shell like separator between the outer and inner layers of fibreglass to make a sandwich construction, if you have damaged the inner layer of fibreglass you will have to repair that first or the sandwich construction will not apply any more and all structural integrity has been lost.
However if you have only creased the outer layer of glass and creased the divynicell you can fill it with a epoxy filler and then glass over that, I do not recommend Qcell for this type of work at all unless it is a very minor crease..
If you want more information or advise you can contact me.

Allan......

Al -

Sorry to confuse the crease is nowhere near that big - it is actually just your standard deck crese that has cracked the rails but not the bottom of the board - in removng the deck to get to the foam i have made an incision that at its biggest would be about 5 inch wide in the middle and 3 at the rails.(going for the diamond pattern) to increase strength and force displacement. Fairly happy with the process of reapir it is just getting the prodicts the fix itself should be successfull - the EPS foam core has a few chinks out of it, what would you reccomend to use to fill in the deck pre laminating? tried a foam filler but it didnt set hard and caused more damage coming off. a poly filler or will this be too hard and make hard points in the deck?

Thanks for the help.

Would a picture help?

Cheers

Keef - work around the corner from that place in unanderra found them not ery helpfull on the phone. What epoxy resin do i need, cost (around)? There is a yacht shop local too that sells epoxy resin

B, If you have creased the rails on both sides there is a very good possibility that you have also delaminated either the bottom or the top as well , most likely the top so keep an eye out for that, remember if you are down to the EPS core you have also gone through the fine layer of glass under the d-cell so it is paramount that this is replaced before putting back in d-cell, firstly you will have to fix the chunks of eps that have come out, this can be done with Qcell if that is what you already have as it only has to be as strong as the eps core, however do not do large amounts at any one time as it will generate too much heat and melt your eps core, you will then have to replace the cloth previously under the d-cell this will have to be feathered onto the existing structure ( no butt joins what so ever ) with this completed replace your d-cell, ensure you have no air bubbles under the d-cell ####. then do your top layers of glass ensuring they are feathered into and overlapping the existing glass, then fill the cloth weave with a faring compound, you can use your d-cell and resin for this.. etc., etc...

Allan........

Uploaded some images on my profile of the my board 'pre-repair'.

what do you think, do-able?

Yes - I had planned to take a heap more out of it so the repair is alot stronger - just took the bare minimum in getting damaged deck out.

What do you mean the less bend in the d-cell the better?

i am an ICU Nurse and we do alot of wounds using vacc techniques so from the reading and the pre-tests i have done i am happy to give it a go.



had planned to use a constant 4kpa to vacc?

Half atmospheric pressure.
how long under accum do you suggest?

will sort it - we use vacc systems all the time. They are great for re-vascularising tissue on the wound (up the blood flow).I would suspect that the d-cell will allow air to draw out through its cell as well? i am aiming for a complete bonded seal with absolutely no air?

id be inserting a couple of diivinicell glass or carbon laminated stringers(about 12"x2" deep)about 4" either side ove the center line, in that job you could have a fine crack in the core, you never know you could fix the top then the bottoam could give away

Sorry nebs you have this wrong, in this case the d'cell is just a butt join, no overlap, so old d'cell should be cut square, and new d'cell the same shape as the hole in the old.
The overlaps are only in the top and bottom glass layers.
d'cell is for compression, glass is for tension.

Yes, don't go any more that half an atmosphere, (you can squash the board with more), and keep it there till resin has set, (leave some in your mixing jar so you can tell)

tapering the d'cell is also an easier method, I use it for small damaged areas, especially if it's hard to remove the old d'cell, without damaging the cloth underneath. But it does mean that the old and new underneath cloth isn't joining as well, there's a tapered layer of d'cell between them.

With be's board there's a major break all the way across the board, if the tension strength of all layers of cloth isn't re-established, the board could easily break in half.
I disagree with keef about stringers, it's very hard to get them to add any strength, don't place any trust in them, just make sure those cloth layers are well connected.