Repairing dings and cracks

 

Hi,

 

I bought my first board (used), and after a few sessions I noticed there are some cracks and dings that I should fix.

I did some research, and think I worked out some steps for doing the repair. I was hoping someone could let me know if my plan sounds good.

Pics of damage:

http://imgur.com/a/jSvht

 

My plans:

  1. Cut away damage, sand w/ 60 grit, clean w/ acetone

  2. Tape off repair area

  3. Mix Q-cell with laminating resin and catalyst

  4. Pour Q-cell in area to be filled

   - use masking tape to shape

  1. Sand excess Q-cell to correct shape w/ 60-100 grit

  2. First 4 mm fiberglass layer:

   - a little bigger than repair area

   - use laminating resin

   - first brush on, then squeegee

  1. Second 4 mm fiberglass layer:

   - immediately after the first layer (w/out allowing first to set)

   - a little bigger than the first

  1. Allow laminating resin to set

  2. Apply sanding resin

  3. Wet sand with 150-600 grit

  4. Apply sanding resin (hot coat)

  5. Wet sand and polish w/ 1000-2000 grit

 

Additional questions:

  1. Some guides say you only use sanding resin. Is worth it to first apply a lamination layer then sanding layer?

  2. Does the ding around the fin plug require any special steps?

  3. Some of the cracks are very small, are all the steps above necessary? Maybe small cracks won’t require filler if I don’t cut out a lot of stuff? Maybe I would only use 2 mm fiberglass on small cracks?

  4. Do I need a gloss coat after the sanding resin hot coat? Is it just for aesthetics?

 

Thanks for any help!

 

heres what i do.  i almost always use UV resin.

 

1st and foremost.  try to be miniminally invasive.

 

remove broken glass

clean up the “shape” of the ding a little

mix lam rez + qcell at least as thick as “mayonaise” the saying goes.  thicker makes for an easier fill but more chance for big bubbles to show up when u sand it.  apply more than enough.  if its a lot of filler kick it slow or it gets super hot.  … i use a grinder to level it so its real quick.  then go back in with block+120 g to fine tune.  best way is to sand the fill and the area the patch will sit, down until you can see a little weave.  makes for a smoother repair.

cloth patch the area.  sometimes single 4 oz, sometimes double 4.  i use a gloved finger mostly, wet the area first then lay the cloth on.  

fair in the cured cloth edges with 60 or 80 g. yes, paper will gum on the lam rez.  make sure you have sanded the entire area where u will hotcoat 80 or 120 g , otherwise hotcoat can flake off when you sand it. acetone wipe the whole ding.

hotcoat.  you can use UV for this part too so its quick and easy.  i uv hotcoat it in the garage.  i keep an eye on letting it self level.  when its nice and flat, move it right into the sun and it bakes in less than 5 mins.  also saves cheap brushes which i never have enough of.  

sand with the highest grit that works .  makes for less work getting deep scratches out when u move up grits.  i go 120 220 320 and sometimes wet 400. done.  if you hit the weave and want to cover it up, re hotcoat after youre done sanding, keep it smoother.

small cracks, i sand down to em a little bit, brush styrene, hotcoat, done.  on bad ones, cloth patch.  styrene makes the hairline crack go invisisble, it is NOT structural or necessary.

gloss aint worth it unless someone asks for it.  

 

enjoy ding repair! try not to breathe too much shit

 

edit- just saw your pics. tail and nose cracks: on my personal boards, i would just sand a little and cloth patch that tail with single 4. if there is broken glass that wants to come out it needs to come out, though.  fin ding: remove broken glass, fill, glass over.

Thanks for the reply! I have a few more questions:

What do you mean by kick it slow? Like stir the filler into the resin slowly?

weave = fiberglass?

 

Does a pint of UV resin last a while for doing these small repairs?

Do you recommend buying only laminating resin and adding the surfacing agent to make the sanding resin? Or do you recommend buying laminating and sanding resin?

http://www.fiberglasshawaii DOT com/resins/resins-solvents/resins-solvents2.html - surfacing agent (wax+styrene)

http://www.fiberglasshawaii DOT com/resins/resins-poly/resins-poly4.html - UV laminating resin

 

Thanks again!

yes weave = glass. You’ll see it when you sand enough. pint is fine to get u started. I Only buy lam rez, mix it to get sanding rez. 4% surfacing agent by volume. in a half dIxie cup, say like 20 drops. 

 

kick it slow means don’t add a lot of catalyst. When resin kicks it refers to reaching gel stage. more catalyst in a large volume of resin: shit gets hot real quick. 

 

if your surfacing agent goes cloudy or bubbles a ton when u shake the bottle, run it under hot water to dissolve the wax again

Uhmm- a few things.

Having looked at the photos, what you have are, mostly, cracks, crunched resin. Now, a lot of people will go overboard on dealing with this sort of thing, me, I say don’t go nuts.

So, how I’d go at it:

  1. CUT NOTHING! PUT DOWN THAT KNIFE/ROUTER/FEROCIOUS SANDER?WHATEVER. PUT IT DOWN RIGHT NOW, BEFORE YOU HURT SOMETHING

A lot of guys get into a lot of trouble by cutting things away that don’t need it, then filling, then glassing over, and the job(s) didn’t need anything of the sort.

I’m serious. You’ll screw it up, everybody does, and then have to take it to somebody like me, and it’ll still look like s#it when I’m done. Again, Cut Nothing.

And now, how to fix it so it looks just like new.

  1. DO sand the areas in question carefully, by hand, with 100 grit paper, nothing coarser. DO NOT use a sanding block. What you are trying to do is get any loose, cracked resin off and absolutely no more than that. If it’s not dented in to a visible degree, it needs no filler… unless you do something foolish like amateur surgery. Don’t even sand down into the glass and definitely not through the glass.

  2. Do you know if this board is definitely polyester or epoxy? A styrene-foam epoxy resin board can be damaged using polyester resin: the styrene thinners in the resin will melt the foam. Find out.

  3. If you have found some spots where the glass is very soft, okay, get out some 2 oz. or 4 oz cloth. Cut small pieces to cover the soft areas and no more. But…if you don’t over sand, you won’t need this.

  4. Tape off the areas to be dealt with. With the resin of choice ( we’ll assume it’s polyester here) and a cheap china-bristle throwaway brush, brush sanding resin (ideally, thinned a bit with acetone) onto the sanded areas. I would avoid UV resin, so that you can do it as a very, very slow batch that’ll harden slowly. Work the resin into the cracks. If you found that you had to use a little bit of light cloth, use the brush to wet out the cloth, in place.

  5. Let the resin dry/harden. Sand carefully, 200 grit or finer paper. Chances are the cracks have sucked up the resin and they are now effectively invisible. Put on another layer of sanding resin if need be, this one not thinned . Sand again, 220, then 300 wet and dry, then finer wet and dry, etc.

  6. Unless you have some polishing compound ( use with a rag and some elbow grease) , you’re done. Step back and admire your work. Again, /these repair(s) done right, is/are invisible.

hope that’s of use

doc…

the fun thing about dings is, everyone repairs em their own way depending on the result they want to see. some guys use ducttape or wax.  some use solarez.  some grind n fill, foam plugs, etc.  my way works well for me, docs for him.  you will develop your own way of doing it too.  dont be afraid of power tools or heavy grit paper.  with a delicate touch, they are a great way to get clean repairs. have fun!   

I agree completely - though I think there’s a special circle of hell reserved for those who stuff wax in a ding and then bring it to me to fix. I charge them triple.

Let me emphasize ‘a delicate touch’. After…let’s just say ‘a long time’ in the trades… I’d like to think I have some skill with power tools and stuff that works fast. As, I suspect, no1 has as well. I definitely have experience. I can do things with a 15 amp sander/grinder that sometimes surprise me…but that’s practice and making mistakes and having to fix the mistakes; some of the surprises were unpleasant.

For somebody starting out in the exciting world of ding repair…and it can be fun, believe it or not…I suggest that you remember ‘First, do no harm’. Go gently and carefully while you get a feel for it, what you can do and what you need to learn to do better. The power tool skills will come in time, they’re all extensions of what you do by hand and when you have those down the power tools come a lot easier.

I did a truly awful repair on my first board, still have the board and haven’t redone the repair on account of it serves as a reminder of how to do it wrong. (chuckling) Plus, it’s my board, and I wanted to get into the water ASAP.

Have fun…

doc…

I’m pretty sure it is polyester. I’ve never seen an epoxy board, but I’ve heard they are more durable. This board is pretty fragile and seems how I imagine a ordinary poly board to be, plus it was custom made in '99. I could be wrong, but I thought epoxy boards are kinda new tech / fancier.

Thank you both for the tips. I’ll try a combo of the 2 methods and let you know how it goes!