Advice on Lng board Square tail repair

Polyester Classic long board with some cracks in the very corners of the square tail.

Wanting to do a solid repair but cant figure out how to wrap the glass well. I realize there is more art to this than anything but can ayone point me at least to a video so i can watch this repair before mucking it up?


Can you post a photo?

Glassing the corners on a square tail is done by stretching the cloth over the corner and taping it well. It often requires a couple of layers done one at a time and sanded in between applications. Pretty basic ding repair. Cut glass patches in an oval shape with the long aspect alinged on the rail apex. Pull the long way first, and tape. Then tape the upper and lower parts while pulling all the slack out.

here is a photo. THANKS

painters tape right ovethe epoxy soaked glass?

Ahm, no, the cloth is warped/deformed/wrapped around the shape in question, you work it gently with your hands. The piece is oversized, and the edges are taped down to hold it  in place. Then you put the resin to it, not necessarily hitting all of the cloth. Let it go off, cut  (carefully) the excess cloth away and sand.  It’s best to use a more loosely woven cloth, it deforms easier. 

I would use a throwaway bristle ( chip) brush to apply the resin, use the tip of it to dab at any bubbles and eliminate them. 

Also, you say ‘epoxy soaked glass’ - if the board isn’t epoxy to start with, there is no need to use epoxy to fix it. Epoxy-glassed boards often ( but not always) are made with polystyrene foam. Polyester resin uses styrene monomer as a thinner/solvent so if it comes in contact with polystyrene foam it makes the foam into goo. Styrene monomer solvent vs polystyrene.  Which is why they use epoxy resin on styrene foam. The chemistry is different. 

But if your board was originally glassed with polyester resin, the foam is compatible and you’ll find polyester resin easier to work with as well as cheaper. 

hope that’s of use



Don’t forget to sand and scuff up the area where you are applying the glass first. Mike

“the piece is oversized, and the edges are taped down to hold it  in place”


Any pictures or videos of that; I cant quite picture it. THANKS

Precut cloth slightly larger than the ding, sand the area around the ding for adhesion. Catalyze and stir about a Dixie cup half full of lam resin.  Using a throw away brush, brush on a coat of resin on and around the dings to be repaired.  Pick up your precut pieces of cloth and apply them to the repair/cracks.  Smooth with your finger and apply more resin as needed to saturate either with the brush or using your fingers.  Brush off any excess resin or drips.  When cloth patch has set, brush on a hot coat (ie “filler coat”). You may want to apply more than one layer of cloth.  That can be done two at a time or each individually.

if the board isn’t epoxy to start with, there is no need to use epoxy to fix it. 

However, if you don’t know what the board was made with, go with epoxy or you could end up with the goo.


you’ll find polyester resin easier to work with

Still trying to wrap my head around that one. Can you explain? 


let us praise the square tail.

standing on the tail in front of the hale in the 

bishop museum all the sense in the world.

a wild eyed critical surfboard engineer

( tthat was adverse to fixing chronic difficult

to maintain hard to wrap corners)

might just reshape the tail round…

yet that is just another can of worms…

spinning the weave 45 degrees 

makes the cloth an easieer wrap.

just another definition of bias

cutting the cloth on the bias wraps contours

most efficiently…   square tails always have two tail dings

round tails only have one.   jut another definition of bias.


oh yeah hi doc!

Hi ambrose. Hope you’re well