Page 1 of 2

Avoiding/covering up breather cloth texture effect.

Posted: Mon Dec 06, 2010 4:07 pm
by JMF
Anyone have any ideas on covering up the horrible textured effect the breather cloth leaves behind after vacuum bagging. I thought of getting some PBT to cover the top but I'm not sure if even this will cover up the textured effect. In my layup I missed a small section and the bag sucking up against the carbon made it glass smooth more to my liking but I'm assuming this method will ad to the weight.

Thanks

Re: Avoiding/covering up breather cloth texture effect.

Posted: Mon Dec 06, 2010 5:06 pm
by zfennell
browse the catalogs for
fiberglass supply or fibreglast distributers.

you can get a perforated release film instead of the woven peel ply.
smooth surface that still allows for resin migration into the breather.
however the amount of excess resin it can handle may be a bit less so you should anticipate that during your layup.

many here figure the resin content is low enough that they simply use a smooth non-perforated release film for a smooth 'out of the bag' finish....your mileage may vary.

regards,
-bill

Re: Avoiding/covering up breather cloth texture effect.

Posted: Mon Dec 06, 2010 6:42 pm
by zob
There is this horible thing caled sanding! :evil:
It takes me more than 1 hour to sand a board. Than wet it out with epoxy again, to get that shiny finish. But it won't be near as good as the finish from the vacum bag.

Re: Avoiding/covering up breather cloth texture effect.

Posted: Mon Dec 06, 2010 8:36 pm
by JMF
Thanks guys, I did use a perforated peel ply with breather on-top of that but I still got the breather leaving a funny texture. I hear you on using just the peel ply, I only used a 300 gram pot on each side to wet out a layer of CF and FG with some reinforcement in between. Going to add another layer of CF with some X-pattern reinforcement to stiffen the board up will try just the peel ply and vac bag, might thicken the pot up with some silica filler.

Some pictures so far. You'll notice the channel running through the middle of the board, I underestimated the power of my pump lol.

Image

Image

Sanding off some flashing

Image

Bottom off the table, butter !

Image

Image

Top surface little ruff

Image

Re: Avoiding/covering up breather cloth texture effect.

Posted: Thu Dec 09, 2010 12:46 pm
by not annonymous
You are probably using polyester batting for the breather. I have found that cotton flannel leaves much less texture, a more even surface, and more even resin distribution.

In the end, there is still no substitute for one or more filler coats and using the sander. With experience, sanding becomes faster and a much less difficult step in the building process.

Trent

Re: Avoiding/covering up breather cloth texture effect.

Posted: Thu Dec 09, 2010 5:23 pm
by duartemv
I've heard that irregular surfaces generate less friction, providing more speed to the board. Kinda like a golf ball.
Why don't you try making it upside down and check it out?

Re: Avoiding/covering up breather cloth texture effect.

Posted: Thu Dec 09, 2010 6:44 pm
by JMF
Yeah was thinking about this about a year ago when I was reading up about Supercavitation. I did have some ideas on how to create a more uniform dimpled pattern similar to a golf ball which but my main aim is to focus on getting this board out before I start tweaking stuff. I had a old Skurfer (Wakeboard) many moons ago before Wakeboarding took off that had a dimpled design, the dimples were huge and not sure if they were even effective.

Re: Avoiding/covering up breather cloth texture effect.

Posted: Fri Dec 10, 2010 10:52 pm
by mthboards
I have been trying to find a way to do this forever without buying the heavy equipment. I can get one good side from a mold but the other side will always be textured because of the vacuum bagging. Thats why most companies use the plastic sheeting Its quick and looks good when its done and it has impact resistance. Decay kiteboards uses two molds top and bottom then compresses them together without a vacuum I think its pure epoxy no top or bottom sheets, looks like they come out perfect. I don't think you can do it that way with a vacuum because you will have trapped air and the only way to get rid of the air is peel ply.
There might be another way but I have not tried it yet.
I just do the sanding method and it takes forever and is messy as hell!
But they come out nice.

Re: Avoiding/covering up breather cloth texture effect.

Posted: Sat Dec 11, 2010 8:18 am
by JMF
Beautiful board MTH. Going to have to do some sanding can't find any PBT sheeting. Problem with sanding CF I've had in the past is that you have to be so carefull that you don't go through one of the layers especially if you are using multiple layers that are misaligned to add more strength/flex. When you go through a layer you can immediately see a change which does not look very nice if you are looking to show off the CF, another story if you are looking at painting over it.

Re: Avoiding/covering up breather cloth texture effect.

Posted: Sat Dec 11, 2010 11:48 am
by everding5792
Ok there is a way to do this its non conventional and i'll probably get some flack. ditch the breather and peel ply and anything else you might have in there, just vacuum down to your smooth table get some cheap super six poly this is you top part of your bag do your epoxy/fiber board layup as before make sure you have breather around the perimeter but not on the finish board surface turn on your vacuum with no wrinkles on the board surface. You will see air trapped between the plastic and the laminate surface you need to squeegee this out to the rails you will remove resin with the air and end up with a reasonable smooth surface, this squeegee part is alot of work it takes 15-20 mins. At this stage you will see how much extra resin is in your laminate as your fiber will be floating in it if you press your finger into the plastic and end up seeing the dimple your not done squeegeeing. Your top surface will still be slightly wavy and you will see any shapeing mistakes, but There is a few other tricks as well too make a totally flat smooth top surface. After you are done sqeegeeing You can create a second vacuum bag on top of your existing still uncured lammed surface place a 3mm plastic sheet material that will conform to your board shape and some breather on it if you like and vacuum this down on top of your board it will smooth out and bridge any slight uneveness If you want to create a chanell in the bottom you will need another layer of 3-4mm waxed for release plastic sheet material use this as a casset to do your layup on then place whatever you want to create the channel under your board on the rocker table surface, and vacuum it down in the first bagging.

good luck
Cheers
Jim