vacuum bagging

General Discussion
1

Hello guys,

at first I have to say that I am German and I apologize for any mistakes I will do in english…

A
friend and me had always been thinking of improve our surfboards, we
only bought two industrial boards, then we started shaping and
glassing. We also startet testing with tails, fins and materials, like
carbon or aramid or xps core.

we only make the boards for us and some really good friends, because the work and the money we have to invest is a lot.

 

my newest board is ready, but I have to admit that I am not 100% happy with the result…

it is a good possibilty to refresh my english posting here btw :slight_smile:

 

we do vacuum bagging with epoxy and it works kind of well, but there are some little things i dont like…

we
glass the board and put the stuff (i dont know the english name) on it
like the fleece and the layer that doenst connect with the epoxy.

then we wrap and fix it with tape and give it into the bag

but the board is a little bit rough and you can feel the glass layer overlapping, it’s not planar or on one level at this point. the difference is about 0.5 mm i think. i could make it planar with the topcoat, but that’s not the perfect way i think?!

and there are some creases… ( right vocabulary? http://dict.leo.org/ende?lp=ende&lang=de&searchLoc=0&cmpType=relaxed&sectHdr=on&spellToler=on&chinese=both&pinyin=diacritic&search=falte&relink=on )

how do you avoid it? especially on the rails?

I read that some guys have a quite perfect board after vacuum bagging. what kind of pressure do you use? I think (not really sure at the moment) we tried it with about 0.7  bar in the bag.

here is a pic of a board which has just been topcoated, that’s why there’s the gloss.

you can see the crease (right?!) on the rail at the nose…

 

It would be great, if you have any tipps for me…or if you see any mistakes, I would be happy if you guys could tell me, esepecially with the creases and the overlapping laminate…

 

thanks a lot!

bye

2

regarding the overlap, you can do a little bit of sanding to take down that lap and then, as you said it will all come out planar/flat with the topcoat.

as for the creases…if you make many relief cuts in your fleec/peel-ply and leave lots of overlap you can hand lap the fleece around the rails very tightly and cleanly.  the other way that creases occur is due to the bag crinkling and pulling tightly around the fleece and laminate. for this you need to make sure that you smooth the bag out as best you can as you pull vacuum. you can also try things like surrounding the board with some soft foam to provide a buffer from the bag pulling and wrinkling the underlying layers.

mine never come out perfect, there’s always a little area here or there that needs to be hand sanded flush.

 

3

 

ah these ideas are good! thank you! i will try it with the relief cuts and if I have something to surround the board, I will do it like that, too.

 

I searched here and in the web for some documentations of vacuum bagged boards, but there is not much to find out about it…I understand that the guys don’t want to tell their experience for nothing, but is their nothing to find out a little bit more of vaccum bagging surfboards?

the only thing I found is that one: http://www2.swaylocks.com/node/1023493

 

thanks a lot!

4

hi Hugo,

there's some interesting stuff here: http://www.compsand.com/forum/index.php/topic,936.0.html

5

hey chrisp,

Thank you, I read a lot about the lap problem in this thread. but it hasn’t been solved yet, no? I did not understand everything, but in my conclusion a lot of the guys have the problem, but no perfect solution has been posted…damn :slight_smile:

I think I have improve my bagging with the tipps above…I have no more ideas…

6

see if you can find some of wouter’s build threads here…he does some pretty neat stuff in the bag.

7

If the creases you’re experiencing are just resin from wrinkles in the peel ply, you can take them down easily with a razor blade at a 90* angle.

8

i have a baggin tip. dont waste your time. makes sweet fuck all difference as to hand lam. other then hand lam looks better. is more waterproof and takes about 1/4 of time with less waste

9

If the creases you’re experiencing are just resin from wrinkles in the
peel ply, you can take them down easily with a razor blade at a 90*
angle.

 

No it’s not only resin its the lam that wrinkeld…

 

i have a baggin tip. dont waste your time. makes sweet fuck all
difference as to hand lam. other then hand lam looks better. is more
waterproof and takes about 1/4 of time with less waste

great advice…then you never surfed a vacuum bagged epoxy board…it’s such a difference…

10

 

 

and you, my friend, have no idea what Silly makes…

 

He’s right and may possibly have tried more composite ideas than most of the non-big-name builders.

 

You should continue to use the search tool, it vastly improves your knowledge.

 

If you really really want to lam your outer glass then you will have to lear how to use a sander and a grinder like a pro because no-one gets a out-of-the-bag finish. Don’t beleive me? ask the windsurf builders…

 

You will need to research:

 

infusion, bleeder foil, breather sheets, resin overflow pots, vacuum gauges…

 

you will need to do:

sand- fair-out- sand some more - more fairing compound - wet sand -  gel coat…

 

 

 

 

 

11

great advice...then you never surfed a vacuum bagged epoxy board...it's such a difference...

(Are you saying that to Silly?) He has vacuumed bagged and surfed more epoxy bagged boards than anyone on swaylocks.

He's back to hand layups I believe?

I have seen hand layup (Not Garage) weight under 4.8 pounds on a 6'0" with the deck ultra strong. NO BAG! Rides unreal.

You can do it in a bag if you don't know how to do a hand layup. It takes more time and you don't gain that much. The key is in the core anyway. Skin is Skin. Core is Core. Both are important. 

Get the facts before you call some one out?

12

Hugo,

It appears from your picture that you are using plain poly for bag material.  Check out this bag material:

http://www.aircraftspruce.com/catalog/cmpages/stretchlonvacuumbag.php

It has much better elongation and will make it easier to get perfect rails and laps.

regards,

Dave_D

13

the guy is clearly new and ESL…no drama necessary.

14

I use the same.

15

im a hack its true. sorry if i was rude, kit and mike sabin and mark venn got finished out of the bag. i know a way how to get almost finished out of the bag. jarrod did too and also im pretty sure coils are out of the bag but then hand filled and sanded. what im seeing in your picture is a normal blank with string and some glass. ( no advantage to bagging and a pretty ugly finish with glass floating on creases and mostlikely pinholes) which will end up sandthroughs and require more glass). here is a waythat i think what would be worth trying

get a large release surface. roll on a layer of gelcoat heat cure style resin let it semi cure. get glass and roll out on top of gelcoat . three or 4 layers of six ounce. use a heat cure infusion resin hand laminate it with a brush or roller . lay on a bleeder and mop to absorb exsess. bag it and pull to high vaccum and get all excess resin from laminate. let it semi cure so laminate is still flexible but not sticky

remove from bag and peel off release then drape it over a board. gelcoat facing up. bag and bake . do the other side.

should end up light and strong 1 pound eps . no stringer

i still think at the very least for a decent board they need a hand done fill coat and sand and finish coat .which doesnt take long if you learn it

the gelcoat idea is optional and you would need to understand the properties of semicure epoxy and if it would actually be flexible enough to wrap  the laps. the reason you would bag on the flat releas is so you can squeze the shit out of it (maybe 15 to 20 hg)so its really low ratio. this sort of pressure would collapse the blank. so after you do the first bag you have the resin/cloth ratio right so you can use 4 or 5 layers of six ounce and then when you bag it on the board you would only need 7 HG . you would be benefit to seal the blank and use a epoxy glue slurry to attach the skin. as you ramp up the oven the precure skin should conform as it becomes more flexible with heat at first and then old temp and then ramp back down. this would also increas the thermal stability up to 120 degress celcious so it would be stable in a hot car.

if you found away to get it to stick to 1 pound polyproplene foam the core would be waterproof and still have memory and flex and also i dont think it outgasse

so f i had the time and resources i would be trying something like this

 

 

16

in production the skins would be done in a stack i guess and the blanks could be hotwire cnc cut flat and rocker pressed in

17

Hi Paul (Silly) -

I can see the benefit of pre-fabbing flat skins but not sure how one would go about wrapping said skins around rails...

Remember the photograph of Bert Burger's shop with the rolls of fiberglass tape hanging from the ceiling?  Assuming he did the prefab skin thing, I think it might also be assumed that the fiberglass tape may have played a role in wrapping the exposed balsa rails.  Maybe apply the skins via vacuum, scuff the overlap areas and hand wrap the rails with the fiberglass tape?  Maybe use resins with different flex properties to wrap the rail glass?  I seem to remember him posting that he used resins with as many as three different flex properties on a single board.

I realize you don't subscribe to balsa as a rail material but the prefab skin/rail wrap technique might still apply?

Stretchlon as a peel ply has always intrigued me as a possible way to obtain smooth outer glass via vacuum bag... punch a bunch of holes in it, pull it tight and secure the underside with tape, poke holes in any little air pockets that might be trapped and slide in to a vacuum bag.  That's basically how Tom Sullivan demonstrated in the sailboard bagging video.

THIS THREAD is always worth a second look although many pictures are missing.

18

Great post Paul!

19

Stretchlon as a peel ply

John it works. Thanks for the tip!

Surfding

20

Hi Surfding -

It has been brought to my attention that there are some thin stretchy perforated release films that allow you to pull the film tight and help alleviate wrinkles...  not sure if it is 'Stretchlon' or other brand name.  Most distributors will send samples.