Cracked board.

[Mikolop1]

Hi, i bought a broken surfboard because it was really chep and i decided to repair it. I am not a surfer, but i am a kiteboarder so i had contact with directional boards before. The board i have is firewire quadraflex 6'2", if even such model exists or existed. Board is cracked all the way from left to right in the middle of the board on the upper side of it. Rails are craked, but the bottom layer of fiberglass or whatever it is, is in good condition. Can someone explain, what i cand do to get this board into useful condition. What repair kit will be big enaught to cover this crack. Do i have to replace a bit of the rail or just covering it up with fiberglass will be enaugh? I dont need full explaination of every small step but, just brief guide becasue detail of one step i can search on the net. Thaks for reply and sorry for any mistakes, english is not my first language.

[jaffa1949]

Sadly because I believe in recycling , I think this board is beyond most repairs.

The vacuum bagging techniques invest a lot of strength in the shells of the skin and the multiple laps of the rails as almost another stringer! The balsa of the rail, if cracked will not contribute to the flex or strength of the board and is like to fail under directional stress. If the balsa parabolic rail is intact your chances may be better.
However I believe there is little or no structural integrity.
So in spite of your best efforts likely to fail again.
Remember too to use epoxy resin or dissolve the EPS foam !
Good luck!

[oldmansurfer]

If you will use it for kiteboarding maybe can fix it reasonably. I would complete the break into two pieces and trim away all the damaged foam and fiberglass. Then fill in the foam defect with something like Q cell then sand that down and do the fiberglass repair with at least 2 layers of heavy glass on both sides (not 4 ounce). The first layer overlapping 2 inches and the second layer overlapping that by 2 inches. I might try to repair the rail stringers with epoxy glue first. before the foam replacement. Anyway the board will be very heavy but if you use it for kiting then not so important? Definitely for regular surfing it will be a challenge but might work.

[Mikolop1]

https://www.cfsnet.co.uk/acatalog/Big-M ... F_500.html
Is this okay for my board?

[jaffa1949]

Absolutely NO
Unless it says epoxy resin. The EPS expanded polystyrene foam with dissolve with normal resin which that appears to be!

If you mix a hot batch of resin it will also melt the foam by heat. Epoxy resins require precise mixing ordinary resins not so much but can be mixed too hot!

[oldmansurfer]

You need to use epoxy resin which is resin that comes in two parts that are generally mixed in precisely equal amounts. The resin you have there is polyester resin and will dissolve the foam in the board you have.