Compsand Community

[Tim]

hey guys,
my glassing sucks. I was really pleased with compsand #1 until I hand glassed. On #2 I'll go with bagging the lam. Anyway, what do you think of grinding it all off to the blasa and bagging the lam? Or live with it and just get on to #2?

thanks!

[paul cannon]

hey tim
im finding that a hand glass job is still the best wrt finish
i think that bagging the outer glass is just complicating something very simple
resin ratios are already pretty low in an epoxy lam so your more likely to get a dry lam if you start bagging
 dry lams are optically not very good because they show the weave
dry lams can also pinhole a lot so you will more likely get water in your skin
my advice would be to get good at glassing before you attemp bagging
bagging add a whole new set of variables and potential problems
not saying it something you shouldnt attemp later on
i just think at thinks stage you will get better results with a hand layup

i have peeled glass off and done it again
but it could be a disaster as well
spraying a colour 2 pac over the top would hide everything
but its prolly better to just make another

what is the problems you are having with glassing
maybe we can give a few tips
theres plenty of glassing vids on youtube that give a fair idea
same thing except you use less resin

[Tim]

thanks for the reply. This board was glassing drama from the start. My additive F had solids in it. I later figured out to heat it a bit to dissolve the solids. It went downhill from there. Trying to separate the deck from the rails from the bottom in glassing; the way I did the 4" rail "tape" glass was a mistake. Lotsa dry spots and then sand throughs to fix. All the fixing got me extra weight. A dry spots don't hide well against the balsa wood background!
I think next time I'll do the rail glassing first one rail a time (board set up on the edge in the shaping stands) with the glass pre wet out. Once that is done I can match up the deck and bottom glass lines for minimal laps.
suggestions?

Tim

[paul cannon]

hey tim
one thing about additives
i believe they are unneccesary
if the resin doesnt work with out adding solvents or wax then its a problem
more complication for something that should be simple!
ive used many brands of epoxy and none of them have required additives


so you are are preglassing the skins then?
i do use that method at times for cosmetics or to save $ on cloth
most of the time i just do a standard hand layup

this is the trick
get a roll of thickish brown paper about 4 to6 oz
this is your wet out material
have the board bottom up
cut flat tape strips across the roll with a cookie cutter on a flat table (this way the cloth wont warp)
or use premade tape (the edges are hard to wet out)
it is easier to use three strips for the rail then one continuous one
have the paper rolled out on your table
place a strip of cloth on the brown paper and gently wet it out with a brush until it is thoroughly wet
do not fold the tape (have it fully extended and straight)
use excess resin so there no dry spots
lift piece of tape off the paper and carefully lay down onto board
and wrap it carefully over the rail with a gloved hand
wet next piece in the same place on the paper

this is pretty much "the way"if your not using bagging
its quick and easy
you just have to control the environment
keep things clean and neat
as shown to me by Mike Sabin

[Tim]

thanks, that sounds good. Do you butt those pieces together or overlap them a little? Once that is done, I imagine; bottom or top lay out the glass and hand lam as normal. How far are you letting the deck and bottom glass over lap the rail glass?

[paul cannon]

um im not sure i know what your on about bro
why are you glassing the rails for if your gunna lam the deck later

that system is for when you glass the skins before you put them on the blank

sounds like you should just glass it like a normal board
check sways theres plenty of threads on it

[Tim]

hi, I guess I misunderstood. I lam'd normally, however, the rails were done with a separate strip of glass from the deck and bottom. In reading as many posts as I could find on Sways there was discussion about keeping the bottom, deck and rail separate. Monocoque construction, etc. Not to tie them together. one quote from Sways in my notes:
2b2 on the bottom and 2b4 on the deck and most importantly only a single strip of 4 oz on the rail

Bert mentioned that he uses 80's style tail rocker which is about 3.5cm to 5cm, your tail rocker at 8cm seems significantly different, perhaps less tail rocker would force it to flex more

berts mentions a balance of glass and lower density eps.
a 7ft board with 3mm deck should flex sweet unless you have
1. too much glass under bottom skin
2. bottomskin overlapping rails
3. too much glass on rail
4. eps is to high density
5. core is too thick"[
 (there was one pic of Bert's that showed the different size glass rolls). Anyway, I used 4" glass from ACP on the rails for the lam. Then barely overlapped that with the deck and bottom glass lamming all three normally. So basically no laps that would stiffen the rail.
What I thought you were explaining was a wet out method for lamming like when you wet out the inside layer.
Am I making any sense yet? Thanks for your time and patience.
Tim

[paul cannon]

hey tim
a big part of the reason a few of decided to go composite specific was because there was a fair bit of bull crap being thrown around at sways
some of it confusing for beginners
and other stuff downright misleasding

normal laps as in normal glassing (say single 6 oz) has very little influence on flex
there is no real difference ,the more rail glass the better
i use at least 6oz on my personal boards and 6 to 12 oz on boards i sell

the reason why peoples use tape on the rails is for ease of production and or cosmetics
the skins are preglassed flat, then put on the board
then cleaned up and the rails are glassed with tape

my advice is not to read to much into glassing methods or skins overlapping  wrt to flex
core thickness/density and shape and the longitudal stiffness of balsa are biggest factors

guys have been chasing there tails (including myself) on flex
just go back to the basics!
and glass it like a normal surfboard (less glass i okay if you want a light one)

[Tim]

thanks Paul, that clears up a lot!

[Kit Sidwell]

Gidday Tim,
Like Paul said,compsand laps and glassing of the rails are not as critical as they are for Pu/Pe construction.
With Pu/Pe's, the laps are one of the major components that strenthen the board.
Too little, and they snap.... too much, and they're heavy!

With compsand, the strength is gained from the sandwich construction, and solid rails.
I tape the rails if I pre-fab the skins with outer glass, otherwise I glass it like a Pu/Pe, but the laps are really short, they overlap each other only by an inch or so.
There are many different methods, but you really only need one layer on the rails, but 2 is fine!

The thing to remember is that the outer glass is only a thin laminate compared to a Pu/Pe's.
Say, 2 - 4 ounce, compared with 4 - 10+ ounces, and with Pu/Pe they are lapped back on each other giving a huge amount of glass on the rail, especially on the deck-side of the rail.

Hope this helps!

Kit

[Tim]

thanks for the input. I haven't had any decent waves yet try the board out on yet. It did come out too heavy (no scale to weigh it on) and it seems stiff.
Is it heavy due to my glassing? Or the stiffness a combo of the glassing and too thick of skins? I did the stand on it "flex test" and it don't bend too much!

[Kit Sidwell]

Yeah, i've found the weight can creep up on you really easily!
The extra resin that you always seem to need to add to get the cosmetics good, really can blow out your weights.
If you weigh everything, keep track of where it's all going, and try and make the build process as smooth and direct as possible, then you'll optimise the resin you use.
I'm a bit paranoid, I even weigh my brush before and after use so I know how much resin is left soaked up in it!
I figure if you are careful how much resin you use, and how evenly it's distributed through the laminates, (no pooling, soaking in, etc) then the board will come out stronger, at a lighter weight.
A good traditional polyester hand laminator is really skilled at churning out boards that have tight, even lams, and minimum soakage into the foam.
With epoxy and compsand, you can go one better, by using things like wetout tables, so that your resin is calculated to the gram.
If your concerned with weight, i'd reccomend weighing every component, and the weight of the board at each stage. Then you know exactly where the weight is coming from, and you can tweak your build schedule on the next board - for example, I know that with my skins, I can calculate exactly how much weight I will add/subtract by changing their thickness.
I can predict within about 5 ounces what weight a board will turn out at, before I even start building it.
Thats if everything goes to plan of course! 

[Tim]

I used 1lb. foam with 2.3 oz. inner glass. The bottom skin was 3mm and the deck 5mm planed down to approx. 3mm. 4 oz. glass for the lam top and bottom. I ended up with two layers of 4 oz. tape on the rails
It's 2 1/4" thick on the rails with a concave deck 2" at the midddle. The rails were 4 layers of the 5mm balsa.

[paul cannon]

that sounds a perfectly respectable build
shouldnt have been more then 5.5 pounds on that schedule
stiffness could be any number of reasons
excess inner resin and to much vac could be it!
your rails are pretty wide for a shortboard
15 mm is about plenty
balsa may have been particularly stiff along the grain
basically you got to check everything as your building it
glass is the least likely culprit if your only using 4 oz

jus wait till you surf it
it may light up in the right conditions
i honestly cant judge a board unless the wave is long enough to link at least 3 turns

[Tim]

the vac was set to 7hg and it ran for 24 hours on the bottom and 16 or so for the deck. The rails ended up being thinner after after shaping so I'm probably in there at 15mm or so.

thanks again for the replies!!!