Vacum pumps

[angus]

I'm planning on making myself a carbon boom (allies to hard on the head) any surggesttion as to what to use for a vacum pump? baring in mind a may go on to make other bits possibly even a boat if I get really ambitous. Somebody suggested a milking machine but I cann't see any of the local farmers lending me one!

[THG]

Angus - you could try the Cherub web site and see if they have any local techies to help you out - they seem to be supportive of other classes doing home builds - they also have some good guides on how to / how no to for foil & spar building.

Kean

[Alex D]

I just picked up a couple of these off ebay (see Classic L25).

http://www.piab.com/Templates/Page.aspx?id=138


Worth a try I thought.

What is the ideal flow rate and pressure?

[FuzzyDuck]

Alex,

We use the Piab units in the company I work for and personnaly I would not recommend them for this application.  They work on a venturi principle of blowing compresse air over an orifice to suck the air out.  The disadvantage is that the compressed air is blowing into the atmosphere for the entire curring period. Thats a long time to have the compressor going at full flow, as well as noisy.

If you can get to Essex I have a Busch Vacuum pump in my factory which i can loan out long term. The only disadvantage is it a 3 phase 240/440V 50 Hz.  This will suck 220-260 m3/hr so should be more than sufficient.  Just leave it on and it will hold the vacuum as long as required.

If you dont have acces to 3 pahse supply you can run this off domestic mains with an inverter, which can be hired.  If you are interested let me know and we can arrange something because I wouldn't mind a Carbon Boom!

Simon
N3230

[Alex D]

Good points about the setting times and keeping the compressor running.

It was Angus who was looking at carbon booms, so over to him on that one.

[FuzzyDuck]

Sorry Alex, short term memory loss has alway been my problem!!!

But if anyone want to borrow the vacuum pump let me know.

Simon
N3230

[angus]

Thanks for the offer Simon, but as I'm based just south of Perth it is rather a long way to come and collect.

[merlinchris]

Hi Angus

The alternative to the vacum pump is to use a female mold and rubber bladder and  pressure pump. This is the method used by Alan Jackson to build his carbon masts. Also used by John Williams (Tynemouth)  many years ago to build carbon boom for his N12 Squidgy Bits (design and mast for his Int 14. He kindly sent me a description of how to do it. Seemed an easier method than trying to remove the finished product from a mandrel. The boom for Squidgy Bits  looked effective and lasted many years.
Happy to send you a copy, let me know your email.

chris

[Lukepiewalker]

Aye, vacuum pumps suck...

I'll get my coat....

[janeysailor12]

[quote by=Lukepiewalker link=Blah.cgi?b=Cool1,m=1178661934,s=8 date=1179077870]Aye, vacuum pumps suck...

I'll get my coat....[/quote]


Oh Lukie Pie...you are so damn funny!!!  I LOVE your replies...laughing till my sides hurt!  

Janey

[matt (Guest)]

vacuum pumps are normally used for consolidating reinforcements onto core materials. Tubes can be made successfully without a vacuum pump as you can get shrink tape to compress the laminiates togethor. This is the 'normal' method of consolidation. not sure myself where you get this shink tape but I'm guessing some of the normal suppliers of carbon fibre will supply them. Also will lee of the cherubs has investigates the shrinking characteristics of plain old fashioned masking tape. It seems that the tape can be made to shrink with heat.
Als don't forget that carbon shrinks by 4% when curing so make sure you really wax up the mandrel good and proper.
Matt

[Matt (Guest)]

sorry - I meant brown parcel tape - not masking tape.