Hi,

I've recently dinged my board and would like to have a go at fixing it myself. I've never fixed a board before but have been going through some old seabreeze threads as well as reading through the board lady's page. I have an idea of what I should do but wanted to run it by you guys to see if I'm on the right track.

My board is a Naish Kailua 160l. There are cracks on both sides forward of the mast track and on the right side a ding where an area has been pushed in. I've put some pics below with rulers to give an idea of the scale.

To fix the ding in the first pic, I thought I would follow a similar path to this fix by the board lady - https://boardlady.com/5908.htm, except using fibreglass instead of carbon. And then for the cracks that run back from the ding, and the cracks on the other side, I was going to drill some holes, and inject urethane foam, again following the board lady's advice on her injection page, then sand back and finish with fibreglass and resin.

Does that sound about right?

Also I've searched the web for urethane foam and can't find anywhere in Australia that sells it. However I did find polyurethane foam (e.g. boatcraft.com.au/Shop/index.php?main_page=index&cPath=37). Can I use that instead of urethane foam? If not, does anyone know where I could get hold of some urethane foam?

Thanks
Jonny

Urethane - they will mean polyurethane.
You can buy 2 pack polyurethane foam in cans and it is the standard- but buying 2L for such a small job is not worth it. It goes off in the can eventually, and you will need to measure about 50g very accurately for that job. Forget that. For a simple first time job, and assuming the bottom of this board is just glass over styro with no high density foam layer (as per Naish's website...)


Cut and remove any glass that is fractured and not adhering to the foam underneath
Hopefully you end up with an area not too big and the styrofoam underneath remains flat

Fill the stryo crack with a single pack polyurethane glue like Tarzan's Grip "High Strength Glue" from Bunnings. Don't think mega bond or very ultimate strength or anything is better- no, they are different and most glues will eat polystyrene. This is a foaming polyurethane glue that will fill the void and glue the crack back together.

Sand back the next day

Glass over with about 5-6x layers of 4oz and EPOXY.
NOT surfboard repair kits or anything the ummmm special people at Bunnings tell you will work.

When the glass /epoxy laminate is almost set (non tacky but u can dent it with your fingernail) fill over with epoxy and q-cell mix.

Sand back, then the fun starts to make it match nicely......

Hi Mark, thanks for the advice, I've updated my shopping list accordingly. The painting is going to be a challenge, but even if I make a total dogs breakfast of it, I'll be stoked just to have the board watertight again.

Cheers
Jonny

Follow the advise you consider worthy.
Their is more than one way to bake a cake.
A ding is a thumbnail crunch. What is have is much more than that. YMMV, as would calling it I reckon.

Painting, I m happy with covered, and a entirely different design at times.

fiberglasssupply.com/Product_Catalog/Pour_Foam/pour_foam.html

This is the version of pour foam I use, the 8lb version. It mixes 50/50 and I dont consider it to go off , sitting, unless its not sealed. This , not polyurethane , is used for boats and taxidermy. It is slightly heavier than EPS, is waterproof and lighter than most materials you can use.

The link is USA.

you can google.
are urethane and polyurethane the same , if you like chemistry

^^^ That is indeed polyurethane. Even says so in the desc and for the technically minded, isocyanate and polyol gives it away

Over here that is about $30 USD and for one time repair that may be pricey.
If there is not much fill to be done and is is more about the crack in the styro, the single pack foaming polyurethane glue that sets with ambient moisture is just as strong,cheaper and easier. Even better because it absorbs moisture to set, if the board had some water in it, it works even better

If going the 2pack route, in Oz generally its Erathane GP330

(and no chemically they are not the same. A polymer is many molecules joined together so polyurethane is polymerised (long chains linked) urethanes.
Bit like how styrene resin looks nothing like polystyrene. So it is a bit of an oversight to have a board repair site sayto fill boards with urethane foam as the novice can't find it and gets confused.)

^^^
Mark. Is that the same stuff as the foaming wood glue , ? Moisten both wood parts , glue and clamp together . It also foams and is incredibly strong .

Yes
BUT I have only tried the Tarzans Grip version. Others may have solvents that bugger up polystyrene foam,I dunno

Mark,
Is this the equivalent in the US? www.gorillatough.com/product/original-gorilla-glue/

"...The water activated polyurethane formula expands into materials to form an incredibly strong bond to virtually anything making Gorilla Glue your solution for almost any project or repair."

Appreciate the wisdom.

Mark, You are correct. I am wrong.

I agree its expensive . Since its what I use for other reinforcement I have it on hand. I'm not familiar with the gorilla product, and will look for it.

Just looked and I have that, I will lay some into a old board to see its reaction.

Select to expand quote

Paducah said..
Mark,
Is this the equivalent in the US? www.gorillatough.com/product/original-gorilla-glue/

"...The water activated polyurethane formula expands into materials to form an incredibly strong bond to virtually anything making Gorilla Glue your solution for almost any project or repair."

Appreciate the wisdom.

I tried this , today. It's glue, designed to hold 2 pieces together, according to Gorilla it expands. Its not destroyed EPS so far. It's not designed to fill a gap. I have heard of it being used for board repair. A narrow gap ..maybe.
It sounds similar to : which is what Mark recommended below
www.bunnings.com.au/tarzan-s-grip-250ml-high-strength-glue_p1210339

Yes thats right.
just to confirm- not for filling gaps, only for the styro crack under your repair.
If u need to add more than a couple mm its not going to do it for u.

Correct..... if it expands more than a few mm it is not going to work. You are better off refilling the repair with similar foam block and filler and then covering with glass as Mark says above.

Gorilla glue fills gaps really well and will expand quite a bit to fill a gap but anything more than a mm or two and it is a pretty soft fill.

This might help.. A true Epoxy repair kit .

www.sanded.com.au/collections/surfboard-resins/products/repair-kit-for-surfboards

Select to expand quote

forceten said..

Paducah said..
Mark,
Is this the equivalent in the US? www.gorillatough.com/product/original-gorilla-glue/

"...The water activated polyurethane formula expands into materials to form an incredibly strong bond to virtually anything making Gorilla Glue your solution for almost any project or repair."

Appreciate the wisdom.

I tried this , today. It's glue, designed to hold 2 pieces together, according to Gorilla it expands. Its not destroyed EPS so far. It's not designed to fill a gap. I have heard of it being used for board repair. A narrow gap ..maybe.
It sounds similar to : which is what Mark recommended below
www.bunnings.com.au/tarzan-s-grip-250ml-high-strength-glue_p1210339

From yesterday this has set up. It did not damage the EPS. It did expand but only slightly. This is Gorilla Original Glue. Cost is $5.00 USA for a small one, I think i would be temped to use the Gorilla 2 stage epoxy , same price.
For the purpose that Mark has said, its ok. It's not a repair on its own . Course neither is pour foam.