Forums > Windsurfing General

DIY Vacuum Bagging System

Reply
Created by Kimba > 9 months ago, 17 Jan 2014
Kimba
SA, 458 posts
18 Jan 2014 1:54AM
Thumbs Up

I have just finished a new Vacuum Bagging System to replace my old fridge pump system.

Here are the images of the prototype to assist anyone contemplating a similar build...
















The concept is based on a kit available from Veneer Supplies.com(in the US) but uses a few different parts including an SMC Electronic Vacuum Switch. This system allows accurate control of vacuum pressures without the pump having to run continuously on big jobs. The vacuum reservoirs store vacuum pressure which is retained with a check valve. This allows the pump to start under minimum load.

There is more info on my blog here: whitelionwindsurfing.blogspot.com/2014/01/diy-vacuum-bagging-system.html

sausage
QLD, 4873 posts
18 Jan 2014 1:36AM
Thumbs Up

Do you take orders! Great handywork. In fact it's better than handywork by the looks.

CRO169
44 posts
18 Jan 2014 5:00AM
Thumbs Up

What was the budget?

GusTee
NSW, 265 posts
18 Jan 2014 8:50AM
Thumbs Up

Wow...impressive.
What size flux capacitor does it run?

GusTee
NSW, 265 posts
18 Jan 2014 8:56AM
Thumbs Up

Had a quick look, awesome website / blog...well done!

keef
NSW, 2016 posts
18 Jan 2014 11:01AM
Thumbs Up

tim fantastic, looks like your setting up for infusion , if you have any idea's on making a pot let me know,

Kimba
SA, 458 posts
18 Jan 2014 11:01AM
Thumbs Up

Select to expand quote
sausage said..

Do you take orders! Great handywork. In fact it's better than handywork by the looks.



Haha, no orders but I am free with ideas. You can get a complete fit from Veneer Supplies.

Select to expand quote
CRO169 said...
What was the budget?


I got most of the bits from our old stockpile at work(pump, solenoid, 24v ps etc). The SMC pressure switch was around $200AUD and the check valve around $25AUD. Most of the brass fittings were from B.L Shipways. I got the diaphragm pump free, it is well made and quiet but I am not sure of what a new one would cost.

So all up it probably cost me around $300.
Select to expand quote
GusTee said..

Wow...impressive.
What size flux capacitor does it run?


I run a compact unit but it still outputs the required 1.21Gw

Select to expand quote
keef said..

tim fantastic, looks like your setting up for infusion , if you have any idea's on making a pot let me know,


I have a twin stage pump for high vacuum pressures and infusion. I have however made this system with a outlet to run other pumps through the system and still be controlled by the vacuum switch. This will be handy of the pump fails mid job and I need to swap it out(as long as I am awake...)
Are you talking about a catch pot Keef? I am using another under sink water filter for this(without the filter) as a catch pot/resin trap. I also use one on the line from my degassing chamber.

keef
NSW, 2016 posts
18 Jan 2014 12:31PM
Thumbs Up

awesome stuff Tim your unit cost $300 all up and play with carbon want $150 just for the pot, admittedly it has a pressure gauge but you cant see through it , I haven't used it yet but hopefully it will work , I need to put a paper cup in the jar but at least I can see it filling
www.playwithcarbon.com/vacuum-catch-pot/

FormulaNova
WA, 15083 posts
18 Jan 2014 11:51AM
Thumbs Up

If you want the cheaper way to have an electronic pressure switch, I used this voltage switch and a MAP sensor from a Commodore:

http://www.jaycar.com.au/productView.asp?ID=KC5377

The map sensor needs 5v and puts out a voltage depending on the vacuum, and you can set the hysteresis as well.

One thing I was amazed at was the difference vacuum reservoirs make. I setup two 4" PVC pipes that run along the garage wall and sealed them to use as vacuum reservoirs. I used an air-line fitting on each, and when I plug them in, the compressor cycle times change dramatically. It goes from cycling every 30 seconds or so to every 15 minutes or so. So much better.

I have read of people using LPG cylinders as reservoirs. Sadly, I think they are better in that the volume is close to what I got but take up a lot less space. I am not sure how they connect the vacuum lines to them though. With the PVC, you can just drill and tap the plastic and it seals well.

Bertie
NSW, 1351 posts
18 Jan 2014 3:27PM
Thumbs Up

Top stuff Kimba.

Now what do you intend on making with your new toy??

Have you considered using vacuum level from inside the part rather than just inside the accumulators to actuate the pressure switch ? There by giving you more control on the vacuum on the actual part.

decrepit
WA, 12761 posts
18 Jan 2014 3:30PM
Thumbs Up

Kimba, great job mate, looks a hell of a lot better than mine.
Mine's very Heath Robinson, bits and pieces from all over with wires and tubes in all directions. Pressure gauge is an old automotive Intake manifold vacuum gauge, I normally run it on "fair"

That's a better idea Bertie but a bit harder to do, guess you'd need 2 lines going to the job.
I think my sensor is too close to the pump, but I'm using the biggest gas bottle as reservoir, normally cycles between 2 and 5 minutes depending on seal.

Hysteresis was my problem, my sensor has none, was cycling much too fast initially. I had to incorporate a time delay into the cct, otherwise the motor would continually be in the start cycle.

Keef, did you make that carbon lid? The first trap I made, the lid caved in, should have thought to make a carbon one.
I use my trap mainly for sucking water out of boards, don't think I'll get into infusion.

keef
NSW, 2016 posts
18 Jan 2014 8:53PM
Thumbs Up

Select to expand quote
decrepit said..
Keef, did you make that carbon lid? The first trap I made, the lid caved in, should have thought to make a carbon one.
I use my trap mainly for sucking water out of boards, don't think I'll get into infusion.

mike I stuck 4 or 5 layers of carbon in the bottom of a round plastic container and stuck the lid in it , theres heaps of carbon
im doing the infusion just as an experiment , Kimba will cringe at what i'm doing heres the plan

i'm making the fin mold out of polyester surfboard resin and suncure rather than mekp , hopefully no shrinkage , ill be laying the edges of the fin and gaskets up with roving's and polyester filler resin, with some roving matting so I have a clear mold again hopefully no shrinkage

for the long base fin ill have 3 resin inlet ports and of cause one into the pot , maybe im dreaming but I've got the pot and ready to go




decrepit
WA, 12761 posts
18 Jan 2014 9:20PM
Thumbs Up

Don't you need 2 pots? 1 for the resin supply, and 1 for a trap?
Oh I guess the resin supply is at atmosphere, just needs a hose into the resin.

Kimba
SA, 458 posts
19 Jan 2014 1:16PM
Thumbs Up

keef said..

awesome stuff Tim your unit cost $300 all up and play with carbon want $150 just for the pot, admittedly it has a pressure gauge but you cant see through it , I haven't used it yet but hopefully it will work , I need to put a paper cup in the jar but at least I can see it filling
www.playwithcarbon.com/vacuum-catch-pot/


Hi Keef, are you using clear vacuum lines - then you can time the clamping before it reaches the resin trap.

FormulaNova said..

If you want the cheaper way to have an electronic pressure switch, I used this voltage switch and a MAP sensor from a Commodore:

http://www.jaycar.com.au/productView.asp?ID=KC5377

The map sensor needs 5v and puts out a voltage depending on the vacuum, and you can set the hysteresis as well.

One thing I was amazed at was the difference vacuum reservoirs make. I setup two 4" PVC pipes that run along the garage wall and sealed them to use as vacuum reservoirs. I used an air-line fitting on each, and when I plug them in, the compressor cycle times change dramatically. It goes from cycling every 30 seconds or so to every 15 minutes or so. So much better.

I have read of people using LPG cylinders as reservoirs. Sadly, I think they are better in that the volume is close to what I got but take up a lot less space. I am not sure how they connect the vacuum lines to them though. With the PVC, you can just drill and tap the plastic and it seals well.


Hi FormulaNova, I was looking into the cylinder option but chose class 12 80mm pvc(100 would be shorter) as I had some spare at work, the class 18 caps were only $3 direct for the distributor. If you are to but the caps locally they can be up to $15 - robbery! As you say they can be easily tapped with any thread type. I used some OLD pvc pipe cement and ended up having some leaks(dropped about 0.1kpa/s) and so filleted all joints with silicone, minimal pressure drop now.


Bertie said..

Top stuff Kimba.

Now what do you intend on making with your new toy??

Have you considered using vacuum level from inside the part rather than just inside the accumulators to actuate the pressure switch ? There by giving you more control on the vacuum on the actual part.


Hi Bertie, a couple of Boards are in the pipeline. First up is a Lake George speed special called the HD Creeper 48 (Hemer Design 48 x 245), templates are cut, the foam monolith is in the shed, just finishing off a NEW hotwire bow with proper power supply.

I will measure the part pressure with an analogue gauge and have the option to control the part with the digital switch. I will start out with it on the vacuum reservoirs first and see how it goes. If I place it on the part and have a blockage or uneven pressure I could pull higher pressures elsewhere and damage the board, this is greatest concern and may not be an issue but I have not tried it this way before.
decrepit said..

Kimba, great job mate, looks a hell of a lot better than mine.
Mine's very Heath Robinson, bits and pieces from all over with wires and tubes in all directions. Pressure gauge is an old automotive Intake manifold vacuum gauge, I normally run it on "fair"

That's a better idea Bertie but a bit harder to do, guess you'd need 2 lines going to the job.
I think my sensor is too close to the pump, but I'm using the biggest gas bottle as reservoir, normally cycles between 2 and 5 minutes depending on seal.

Hysteresis was my problem, my sensor has none, was cycling much too fast initially. I had to incorporate a time delay into the cct, otherwise the motor would continually be in the start cycle.

Keef, did you make that carbon lid? The first trap I made, the lid caved in, should have thought to make a carbon one.
I use my trap mainly for sucking water out of boards, don't think I'll get into infusion.


Thanks Mike, I thought it looked quite Mad Scientist like...

I think the hysteresis is adjustable on the gauge and I will aim for a nice compromise, at the moment it is running about 5kPa past the set point. I am sure the cycle time will be different once I am bagging boards.

nebbian
WA, 6277 posts
19 Jan 2014 12:09PM
Thumbs Up

Select to expand quote
Kimba said..


Hi FormulaNova, I was looking into the cylinder option but chose class 12 80mm pvc(100 would be shorter) as I had some spare at work, the class 18 caps were only $3 direct for the distributor. If you are to but the caps locally they can be up to $15 - robbery! As you say they can be easily tapped with any thread type. I used some OLD pvc pipe cement and ended up having some leaks(dropped about 0.1kpa/s) and so filleted all joints with silicone, minimal pressure drop now.



I had a similar problem with, of all things, a chook watering system. I needed a reservoir that could handle the vacuum that a metre of water pulls, no problem I thought, just use 90mm PVC.

Well a month of slow leaks later I tried filleting everything with silicone, that lasted OK for a while but eventually let air back through again. Since I'd actually found where the leak was I cut that bit off and started again with new joiners and LOTS of PVC cement, no leaks now.

I'm amazed at how persistent vacuum is at finding the smallest pinhole... way harder to seal for vacuum than it is to seal for pressure.



Subscribe
Reply

Forums > Windsurfing General


"DIY Vacuum Bagging System" started by Kimba