This is an example of a basic ding repair.  The techniques used here can be applied to other kinds of dings as well however some modifications may be necessary.  This technique will not allow you to repair serious damage where part of the board has been destroyed.

Step #1:  Analyze the situation.  How bad is the ding?  Has the ding weakened the board structurally?  This guide is intended to tell you how to fix minor dings only.  If the ding is mostly cosmetic, this guide can help you fix it.

Step #2:  Make sure you have everything you are going to need before you start.  A good way to do this is to read this entire guide carefully before hand and to think out every step ahead of time.

Step #3:  Grind out the ding so that the damaged area is completely removed.  Generally you do not want to destroy the bottom of the board at all.  Instead use a Dremel Tool to carve out damaged foam and fiberglass in the ding area.  Don't get carried away.  Just carve out the damaged areas.  There should be a nice clean hole when you are done.

Step #4:  Sand the affected area.  Sand the entire area  including the immediately surrounding area.  You want to sand all surfaces that will be bonded to.

Step #5:  Clean the affected area by blowing off all dust and then wiping it down with acetone or rubbing alcohol.

Step #6:  Cut your fiberglass.  Always make your cuts at a 45 degree angle to the weave.  This will help the cloth keep from falling apart in your hands later on.  Make sure the size of your patches are large enough to cover the entire affected area and some of the surrounding area.  When in doubt, cut them too large rather than too small.  You want to cut four pieces of cloth if you are using lightweight (4oz or 6oz) cloth.  If you are using carbon fiber cut one patch of carbon and three of fiberglass.

Step #7:  Mix your resin and catalyst together using the ratio required for your specific resin.  Stir thoroughly.  You won't need very much resin.  1/3 cup will almost always be enough.

Step #8:  Add your filler(s) to the resin.  There is no exact rule but generally you want to use one lightweight filler and one structural filler in your mix.  One common combination is to use cabosil and milled fiber at a ratio of 3:1 (more cabosil).  Add in a small amount of each and stir it all in, then add more if necessary.  The goal is to get it to the consistency of peanut butter.

Step #9:  Take the thickened resin and get a good blob of it on the end of your tongue depressor.  Smear the resin into the void you grinded out earlier.  If it is a particularly bad ding such as the one pictured above you may have to rebuild the nose a little bit with the thickened resin.  This can be a very hard thing to do.  Make sure your resin is thick enough and have some patience.  It may take some time to get it just right.

Step #10:  Depending on how damaged the nose is you may want to stop at this point and let the filler cure.  This allows you to reshape the nose before applying the fiberglass.  If the damage is minor however, you can do it all in one step.  Go back and get your fiberglass.  Mix another cup of resin (partial cup).  Brush some resin onto the affected area to help the fiberglass stick.  Lay the edge of the cloth on the top of the board and work downwards making sure that the glass makes contact with the board in all places.  For minor dings you do not have to wrap the cloth around on to the bottom of the board.  You can just leave it hanging downward and then trim the bottom with scissors (while wet) or grind/sand it off (if cured).  If you are using carbon fiber, make sure that it is on the bottom (touching the board), otherwise you will just sand it off.  This is often the hardest step.  Have patience and you will get it right.

Step #11:  Let the resin cure.  This can take anywhere from a couple of hours to 2 days depending on the temperature and the kind of resin you are using.  Heat makes most resins cure quicker so you may want to put it in the sun.  Wait till it is fully cured to sand it.  It will make your life easier.

Step #12:  If you have a grinder or grinder attachment use it to carefully sand down the repaired area so that it is almost flush with the board.  Do not sand too far because you will go right through the board and into the foam!  If you do not have a grinder you are going to have to do a fair amount of hand sanding.  Get out your rough grit paper and start moving.

Step #13:  Sand "the rest" of the way by hand using rough then medium and finally fine grits.  When you are done the surface should be "baby soft".

Step #14:  If you did a carbon repair you can make it look prettier by waxing the board so that it all looks the same.  An even easier way is to smear surf wax on the ding repair and let it melt in the sun.  After it has fully melted you can wipe it off with a paper towel.  This usually makes it look much better.

Note:  This is actually the quick way to do this repair.  When you have to rebuild the shape of the nose the best way to do it would be to add another step.  You would want to let the resin cure after smearing the resin into the void and rebuilding the shape of the nose.  After the resin cured you could sand the exact shape you wanted out of the resin.  Then you would be ready to lay the fiberglass on top and proceed as above.