Forums > Windsurfing General

Repair your own boards, like a Boss..

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Created by barn > 9 months ago, 31 Jul 2011
TerryF
WA, 52 posts
1 Aug 2011 11:16PM
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Hi Barn, thanks for posting this info in response to my earlier post. Luckily my two patches are nothing close to a snapped board.

GusTee
NSW, 262 posts
2 Aug 2011 9:46AM
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Excellent posts....Thanks for putting the effort in with photos and diagrams.

Where's the best place to shop for the repair materials mentioned?

leto
273 posts
4 Aug 2011 9:49AM
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Barn, the method you described is super cool and better than the one from Boardlady. A PhD student would modify it a bit to avoid using any metal tools and have more control...
Then it's perfect and i'll use it for my future repairs... :)

Here is what I would do to make it simpler and more streamlined...

Modification on how you prepare the bottom layer:

I would take a strip(s) of glass/carbon of the right size and lay it on a piece of glass/flat plastic bag/an instant wrap, and cover it with epoxy and let it dry. You will get a nice thin, sharp, flexy, manageable piece of material afterwards which you can cover with more epoxy and squeeze pretty easy under your shell and over the EPS foam. You can even play with injectable polyurethane foam if you wish it to be squeezed more from the bottom up. You can even flip the board and add hang some light weights to insure it presses nicely against the bottom layer..
After this procedure everything is simple.. add divinicell, cover with more glass/carbon..

fullmoon
WA, 314 posts
4 Aug 2011 11:13AM
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decrepit said...



I tend to agree with Mark, I don't like what I can't see


Yep.I'm with you both on that one.

Great link swoosh,really interesting.

barn
WA, 2960 posts
4 Aug 2011 1:00PM
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fullmoon said...

decrepit said...



I tend to agree with Mark, I don't like what I can't see


Yep.I'm with you both on that one.

Great link swoosh,really interesting.


Must get nervous laminating a whole PVC sheet onto a board..

I am not fazed by the 'old guard' not embracing new, superior solutions. It's human nature to stick with what your good at, right or wrong.. The caveman that changed his Flint technique each week while trying to keep up, usually went hungry..

Old skills or ideas never get abandoned, they get forgotten..

So I will put all the repairing methods to the test is some filmed experiments over the next few weeks.. But until then, in honor of human stubbornness and bad ideas, 9 minutes of flight attempts..

#at=482

CJW
NSW, 1718 posts
4 Aug 2011 7:26PM
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leto said...

Barn, the method you described is super cool and better than the one from Boardlady. A PhD student would modify it a bit to avoid using any metal tools and have more control...
Then it's perfect and i'll use it for my future repairs... :)

Here is what I would do to make it simpler and more streamlined...

Modification on how you prepare the bottom layer:

I would take a strip(s) of glass/carbon of the right size and lay it on a piece of glass/flat plastic bag/an instant wrap, and cover it with epoxy and let it dry. You will get a nice thin, sharp, flexy, manageable piece of material afterwards which you can cover with more epoxy and squeeze pretty easy under your shell and over the EPS foam. You can even play with injectable polyurethane foam if you wish it to be squeezed more from the bottom up. You can even flip the board and add hang some light weights to insure it presses nicely against the bottom layer..
After this procedure everything is simple.. add divinicell, cover with more glass/carbon..




A good idea...not so much. There are two glaringly obviously reasons why this would never work, not to mention the rest. Rather than go through them lets just dismiss this suggestion as madness from the outset and move on

R1DER
WA, 1461 posts
4 Aug 2011 7:08PM
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WARNING! WARNING! WARNING! to anyone attempting to do a board repair like this.
This is not the strongest way, yes it might hold up for a while but it will break earlier than a better repair.
just doing a straight line of glass across the board creates a stiff breaking point.
It's a bit like scoring a straight line along a piece of glass before you snap it.
the top glass should be curved or a diamond shape to spread/feather out the stiffness/load.
I fully concur with Mark Australia

decrepit
WA, 12093 posts
4 Aug 2011 7:21PM
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barn said...
>>>>

Must get nervous laminating a whole PVC sheet onto a board..

>>>>>>>>



Nup, I can see how well the glass is spread out before I put the PVC on top of it.

Poking glass under another layer is working blindfolded.
Be interesting to pull it apart afterwards to see just what's happened.
If the glass is nice and straight without any folds, creases or tears. And no holes in the foam, then you have a viable technique, as long as you can always repeat it.

I admit, removing a strip of PVC without damaging the underlying fibreglass, isn't easy, and would be harder and slower than your method. But as you say it's what I'm comfortable with, and is at least as strong, possibly stronger.

barn
WA, 2960 posts
4 Aug 2011 8:08PM
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R1DER said...

WARNING! WARNING! WARNING! to anyone attempting to do a board repair like this.
This is not the strongest way, yes it might hold up for a while but it will break earlier than a better repair.
just doing a straight line of glass across the board creates a stiff breaking point.
It's a bit like scoring a straight line along a piece of glass before you snap it.
the top glass should be curved or a diamond shape to spread/feather out the stiffness/load.
I fully concur with Mark Australia


The my chosen shape of this particular repair is not the point of the method. But In my defense..

There is no straight line, it's a tapered repair, as in each layer of glass extends further than the last. Plus, in theory, the repaired layer is no stronger, or weaker than the original board.. Because the repair is built just like the board..


In theory, if there was a long strip of EPS backed PVC repaired like this it would bend with the same characteristics as the original..


So this is why I went with the visually straight line, along with the fact it's just a cheap freeride board, this seemed the best option.. Otherwise I am half way to replacing the whole deck!!

Below I have drawn the repair cutouts I am assuming is being suggested over the straight.. I have also shown how the glass is stepped, so any forces or 'weak or strong' points are distributed over a 20cm area...


If you go to bunnings, there are lengths of pine that have had the Knots removed and the wood is finger joined back together, the cut is a straight line..

The join in a carbon mast, is a straight line..

barn
WA, 2960 posts
4 Aug 2011 8:14PM
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decrepit said...

barn said...
>>>>

Must get nervous laminating a whole PVC sheet onto a board..

>>>>>>>>



Nup, I can see how well the glass is spread out before I put the PVC on top of it.

Poking glass under another layer is working blindfolded.
Be interesting to pull it apart afterwards to see just what's happened.
If the glass is nice and straight without any folds, creases or tears. And no holes in the foam, then you have a viable technique, as long as you can always repeat it.

I admit, removing a strip of PVC without damaging the underlying fibreglass, isn't easy, and would be harder and slower than your method. But as you say it's what I'm comfortable with, and is at least as strong, possibly stronger.


I agree it's blindfolded, and there is no doubt some skill involved.. The glass can tear, and it's best to have a very bunt probe, and also be quite liberal with the resin.. No use being Conservative while trying to hold things together..

I have opened up a board with a repair like this after it was destroyed in a separate accident and the blind spot was all stuck together ok.. It was a Tabou Pro edition though, so the EPS was hardly stuck to the skin anyway!

Brien
NSW, 172 posts
4 Aug 2011 10:17PM
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Interesting thread. I tend to agree that poking glass under the bottom layer seems a bit agricultural but it would be interesting to see what sort of shape that bond was actually in once it was set and if there was any real strength in it. That aside, if my memory of composite construction serves me correctly I believe that the bottom layer of glass would actually be in compression after landing a jump and the top layer would be in tension. As such the strength of the bottom layer of glass would not contribute very much in comparison to the top layer.

decrepit
WA, 12093 posts
4 Aug 2011 8:37PM
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Yep, you're right, the area of the deck between mast track and footstraps is under tension when a jump is landed.
But I've seen this area fail, because rider puts front foot forward while slogging, in that case the underneath layer is in tension. I agree with Barn, in structural areas, it's best to reproduce the original sandwich as much as possible. A sufficient overlap of top and bottom fibers ensures the same tensile strength.
But I guess it could be argued that the overlapped area is stiffer.
Like Barn I'm not convinced this is a problem. Relative to the stressed area, the overlap is very short. I can't see it increasing the stress at the transition significantly.



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"Repair your own boards, like a Boss.." started by barn