Article 8298 of alt.surfing:
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From: conrad@jtec.com.au (Conrad P. Drake)
Newsgroups: alt.surfing
Subject: FibreGlass FAQ - part 1 of 2
Date: Mon, 17 Oct 1994 05:22:05 GMT
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Someone (well C. Myron Ware cmw@hobbes.larc.nasa.gov, actually) asked for the
FibreGlass FAQ. So here is the current revision, in two parts.
Conrad Drake
Changes from 0.1 - clarified the basic steps
===== Fibreglass repair FAQ 0.2 17 Oct 94 ===== Part 1 of 2
This FAQ looks at (Part 1) fixing dings in "conventional" surfboards and
(Part 2) some other materials and other uses for GRP.
Thanks to (at least) for comments, advice and comments that I've ruthlessly
plagerised without permission.
tele1@eternity.corp.sgi.com (Eric N. Valor - Ding Repair Suggestions)
ttweed@ucsd.edu (Tom Tweed - setting fins)
flynn@cats.ucsc.edu (Eric Flynn - building a board)
dmp@bmesun1.MCG.EDU (David M Parrish - aircraft epoxies)
Charles.K.Scott@dartmouth.edu (Charles K. Scott - more aircraft stuff)
1. Fibreglass for Surfboards
------------------------------
Dings
Ding Repair Suggestions
Setting Fins
Building a Board
GRP - Fibreglass and resin sources
2. Other Stuff
--------------
Epoxy and Other Materials
Some Books
Composite Workshop Review
Fibreglass Update
**********************************************************************************************
1. Fibreglass for Surfboards
------------------------------
Dings
-----
For small holes - pre-mix microballoons with resin (50:50 by volume). Add catalyst
as normal: ie 7-8 drops MEK per 20ml of resin (more if cold, less if hot weather).
For big holes - clean out the hole, cut a chunk of foam to fit and stick it in
with resin. Shape (180 grit) and re-glass.
Reglassing - (torn or missing glass). Remove all torn bits & feather the edges.
Fill any holes or depression with balloons/resin. When hard, sand smooth (80 to 180
grit). Cut glass cloth about 1cm too large (as you need a good join & some will get
sanded off) and put in place. Mix a batch of resin. Use a bit of sponge/squegee
to apply resin to totally wet the glass. Then use the sponge to remove all excess.
Do this by dabbing/wiping with the sponge, periodically squeezing out the sponge.
The finished surface will have the texture of the cloth.
Once this has set, sand (w' #80-180) to remove rough spots and to smooth the join
between old & new. This also keys the resin for the hot coat.
Mix another batch of resin, this time 'hot' (extra MEK - 1 extra drop per 20ml).
This will gell really quickly (5-10 minutes). Brush on just enough to
provide a smooth finish. When set, sand smooth with progressively finer paper
(180, 240, 400, 600 then cutting compound) until either bored or satisfied.
If you cut through to the 'glass, you _should_ repeat the process.
[Mals tend allways have this second gell coat, and are highly
polished - OTOH competition boards are often not even sanded at all.]
Resin, MEK and microballons can be bought from most shapers. Offcuts of foam
and cloth can usually be scrounged from the same sources.
The process I've described is time consuming and most shops don't do that when
they "fix" a ding. They mix up a hot batch of resin with lots of
microballons and colour, fill the hole & sand. It's quick (only one setting
time vs 3 or 4). It's also weak. Some at least mix some chopped mat in to give
it some structural strengh, but you've still got a future source of leaks.
Oh, Masking tape, Saran/Gladwrap and Aluminum foil can be used to hold resin in place/shape
while it gells. Personally I like alfoil.
Ding Repair Suggestions (Eric N. Valor)
---------------------------------------
(horror story deleted)
First off, fill the holes with foam. Most surf shops that do ding
repair may have some around that they'll flow you. Either that or
find a shaper in the area. But do NOT fill in a hole with just resin;
it makes for bad weight and an ugly repair. Cut out the hole until
it is nice and even, then cut a piece of foam to shape and insert.
Make sure it matches up evenly or you'll get ugly lines.
btw: that powder is most probably microballoons; small glass bubbles
with air. They space out the resin and make it a bit lighter.
Ok, next: Use 10-12 drops of catalyst per ounce of resin. I don't know
how big your dings are, so I don't know how much resin to use. Just
eye it. Stir the catalyst in for about 60 seconds to get a good mix.
Then coat the bottom of the "filler foam" with a bit of resin and insert
into the hole. Then cover with a sheet of fiberglass (cut to shape of
the hole) and pour a little bit of resin on top and smooth it out
over the hole and the existing glass (you'll sand off the excess later).
Put a piece of Saran Wrap over the top and let set overnight.
You can use 80 grit sandpaper to start the process, then once you start
to get down to the existing glassjob, switch to 100 or 120. To finish
off, use 400 wet/dry (and use a bit of water). That should do you.
Fins are a bitch to set properly, as placement of the fins absolutely
determines how the board will respond. Make sure you get right and
left fins for the twins (yes, there are sides) and a normal single
for the rear (this is a tri-fin, right?). Angle them out a few degrees
from straight up-and-down, and toe the front edges of them in just a
bit. This is the hardest part, as they have to be braced while the
resin dries.. it's a bitch and I've only done it (badly) once.
Eric N. Valor
Setting Fins -(Tom Tweed)
-------------------------
A trick that some of my glasser friends use is to set the fins with a bead of
hot-melt glue right on the bottom- have the front and back toe-in marks
penciled on the board, and a little cardboard template cut for the camber
angle (usually about 5 degrees outside of perpendicular to the bottom). Slam
the fin down while the glue is hot right on your marks, slap the camber
template up against the side and hold it steady for 15-30 seconds while the
hot glue solidifies. Voila! You're ready to rope and glass them in without
the obstruction of tape braces, etc., holding them in place. Don't bump them
too hard, though, it's not that strong before glassing....
Tom Tweed- La Jolla, CA e-mail: ttweed@ucsd.edu
Building a Board
----------------
From: flynn@cats.ucsc.edu (Eric Flynn)
Subject: Re: Building a board...
Date: 24 Jul 93 05:40:52 GMT
In article pa_warren@Merrimack.edu (Warren Crossfield) writes:
>
>Anyone here build their own board(s). If so, any tips (materials) for a
>novice builder?
Well it looks like this is a good time to give you all the update on how my
board-building project went. First, a little review.
I have been surfing an old 60's style Team Becker. It's 7'4", kind of half-
way between a longboard and a bonzer. It has a round tail, and a very wide,
round nose, with a large concave. These characteristics give it nice
watch-catching ability, even in small surf, good handling, and it nose-rides
like a champ.
The board I just got finished building is based on this design, and has almost
all the desirable characteristics of its predecessor. I chose to copy this
board because I like it a lot, and the guy who owns it wants it back!
I went to Monterey Bay Fiberglass and purchased all the materials necessary
which ended up costing about $150. I then had a shaper here in town shape
the blank, which cost $70. I was fortunate enough to run across one of the
guys who used to glass for the Haut,and he basically taught me how to laminate.
I paid him for his time, bought him lots of beer, and ran him around town for
a couple weeks ( he doesn't have a vehicle ) in retrun for his help. In the
meantime, we have become good friends, and this worked out so well we plan
to build another board.
The next board will be a 9'3" shaped by Doug Haut, and glassed by me and Jeff
Thompson.
One other stroke of good fortune: Jeff happens to be a personal friend of
Jimmy Phillips ( of Pack-Your-Trash fame ), he talked Jimmy into designing
a custom logo to put on my board. I paid Jimmy for the work, but I can tell you
that I got it at a very handsome discount.
I took some pictures of the new stick before I waxed it, and plan to use the
scanner at work to digitize a few and will post them to the surfing GIF mailing
list. The board came out really nice, and it surfs like a dream.
:-))))))) Yaahhooo!!
So I guess I ought to address the questions asked at the beginning of the
article.
First, it helps _worlds_ if you can find someone experienced to help you. My
board woulda been a giant resin barge if I hadn't had Jeff there to bail me
out of some really sticky ( literally! ) situations. Failing this, at least
get someone to let you watch them glass a side or two so you can see how
laminating is done.
Second, you will need a place to work. A spacious garage is what I used.
You will need an enclosure of some sort for the hot coat and gloss coat,
otherwise the resin may do nasty things like split or get bugs in it.
Next, you will need the following equipment and supplies:
Glassing stands
Grinder or Sander/Polisher - I use a Makita 9207SPC
Paint brushes 2,3,4"
Wide wall-papering brush
Rubber Squeegee
Sanding discs
60 grit, 100 grit Aluminum Oxide
400 grit, 600 grit Wet or Dry
Jars or #10 cans
Canister-style organic vapor rated respirator - IMPORTANT
X# gallons of resin - I prefer Cargill, its stronger than some others
1 gallon of acetone
masking tape - don't get the cheap kind, get 3M paint masking from a paint store
Single-edged razor blades
X# yards of fiberglass cloth
I'm not going to try to explain the whole process, but here are some helpful
hints in general:
A plastic trash bag masking taped around your waist make a cheap disposable
apron. And speaking of disposable, go down to the thrift store when buying
clothes you plan to wear whlie glassing.
Soak your squeegee and paintbrushes in acetone overnight before glassing.
They will be much more pliable and easy to work with.
Tape down a couple layers of tar paper (roofing cloth) on the floor so you
will not leave any post-Columbian artifacts thereon.
Have two pairs of scissors: one exclusively for cutting fiberglass cloth,
and the other for cutting sandpaper and other such things.
When you cut the cloth around the edge of the blank, leave a 2-3" lap,
begin careful not to leave any dangling strings. These will be a real
pain later if you don't eliminate them now.
Use the wall-papering brush to smooth out the fiberglass on the blank.
This helps to avoid the cloth "floating" off the blank.
Laminating has three basic steps: 1) saturate the cloth 2) squeegee out the
excess and 3) work out the cloth to a burlap texture. Start your pour near
the middle and work toward the ends of the board. This is where it gets hard
to explain without someone holding your hand and showing you what to do.
The basic idea is to keep the squeegee vertical and apply just enough pressure
to spread the resin and saturate the cloth. Then, using a bucket to catch the
excess, take firm even strokes the entire length of the board, squeezing the
excess resin out of the cloth. No doubt there will be some dry spots, so use
the resin you catch to thoroughly soak them, and squeegee out the eexcess again.
Once this is done, take medium firm strokes the length of the board, starting at
the middle. The key here is to leave the squeegee in contact with the surface
as much as possible. If you pick it up, you will create a puddle.
The hot coat and gloss coat follow in much the same way, only you use a brush to
apply them.
After the hot coat, use the grinder to sand the board smooth. The fins and
rails should be done by hand. Then wash the board with a soft rag soaking
wet with acetone, much as you would wipe down a table, catching the debris
by folding the rag. Do the same with your bare hand while the acetone is
still evaporating. You will be able to feel when the surface is clean.
After the gloss coat, you have the option of polishing it. I personally think
boards surf just fine unpolished, but a mirror finish on a showroom board
will sell faster to be certain.
NOTE: ALL of the organic chemicals used in surf-board building are KNOWN
carcinogens. Although many people have had long and happy board-building
careers and never gotten cancer, please use all due caution when dealing
with these volatile, corrosive and highly toxic chemicals!
Buy a respirator like the one mentioned above and WEAR it!s
Well, if you all want more gory details, feel free to mail me at
flynn@cats.ucsc.edu, or post a question in reply. I'm pretty new at this,
and as I mentioned above this is far from a complete description of the process,
but it should at least give some idea of what you need to know.
Happy board-building!
ERic
GRP - Fibreglass and resin sources
----------------------------------
Fibreglass is more properly known as Glass Reenforced Plastic (GRP).
Most surfboards are built using 1950's materials - plain woven glass cloth and polyester
resin with Methyl Ethyl Ketone peroxide catalyst on a polyurethane foam blank,
reenforced with a single wooden stringer.
You'll have to pay for your resin, hardener and micro-balloon filler. If you know a local
shaper you should be able to scrounge some off-cuts of foam and glass cloth. Rovings (basically
fibreglass 'rope') are usually bought, but if you're cheap, pull apart some cloth.
Boat manufacters usually use either chopped strand mat - which is much weaker than cloth or a
sort of spray gun which pulls in fibreglass rope, chopping it up and sucks up resin, mixes it
with catalyst and the chopped strands before spraying the lot out. Usually into a mold.
Speaking of molds, watered down PVA (White wood working) glue apparently works well. YMMV.
