A mate of mine knocked this up, I’ve tested and it pulls a full atmosphere or as near as any of us need.
The pump is from an old diesel Peugot car, I think it had something to do with the windscreen wiper…The motor is out of a scrapped fridge or similar.
See the pictures at link below. It is brilliant
http://www.photobox.co.uk/album/3882826
Should have credited to the builder, Bog Tyler of Llangwm, Pembrokeshire. A man of great creativity!
Not windscreen wiper, break servo vac pump
Looks pretty decent!
Just be careful with it and use a resin-catch jar inline to stop resin being pulled into the pump!
Hope it works well!
James
Hi,
That looks great!
How powerfull is it? for example, do you think you could vac more than one board at a time? Only 10" - 15" mercury at most for each one of course.
Does it shift a lot of air? Probably doesn’t have a CFM rating, but does it suck the air out of a bag pretty quick?
Sorry for all the questions, it looks pretty slick! Im interested!
I’m happy with my fridge pump setup, but always on the lookout for the next best thing.
I don’t have the money for a rotary vane, and i’m kinda keen to get more than one board at a time going…
From the windscreen wiper? That seems strange, they just have a little electric motor, or a tiny pump for the water squirters.
I’m gunna try and identify what it is, do more research.
Thanks!
Kit
It seems to shift plenty of air, certainly enough to bag one board, coz that’s what I did. If you used a 3 way valve in the line you could pull down one board, switch the valve sealing the line you’ve pulled down, vac the next bag and then switch the valve to pull both bags at the same level. Obviously beware leaks in either as that will reduce the overall pressure in both bags…
Pump was actually a break servo pump from an old Peugot diesel
That’s a great idea.
When I used to drag race, we would use a GM smog pump to pull vacuum inside the engine to get the rings to seal better. It could move quite a bit of air quickly and pull a good vacuum. Maybe it would be an alternative item to use, as we don’t have too many Peugeots in our salvage yards around here.
Thats exactly what my rally-car racing uncle just told me.
Break servo pump!
Diesels engines are hard to pull vacuum from, which is how the power-assist works in vehicles.
So they beef it up in trucks/lorries/big rigs with one of these pumps.
Should be heaps of info online about specifications and stuff, so you know what kind of air it can move.
Japanese vehicles are plentilful and cheap here, so i’m gunna go hunting round the wrecking yards, see if they use them in those ones too. European = expensive in NZ.
Awesome tip, thanks!
Kit
Just added a picture of the catchpot I use, it looks posh and expensive but thats only the digital pressure gauge. No need for anything that fancy, we just happen to have one in the workshop for boats and things (my board building experiments!). Have a look at the link I first posted here.
So, you run it on 12 volts I assume.
Would that be a car battery, or a battery charger?
I’m thinking a car battery with a charger attached would avoid any chance of it running out of power mid-vac.
All the cheap battery chargers probably won’t work just hooked up to the terminals i’m guessing.
Something like that?
Kit
Hi KK, the setup in the photos is a 240v electric motor driving the belt, not batteries. Just plug it in and you’re off, I’ve run it 12 hours without a problem. I guess the diaphragm will wear out one day but it’s checked regularly and easily replaced. another bonus is the very pleasing “puttering” noise it makes but maybe I’m sadder than I thought!
Awesome!
So your just bleeding off pressure, and having the pump constant running?
I made the vacuum switch like on this site http://www.dream-models.com/eco/vacuumpump.html#N100B7
and it works flawlessly.
It’s really sensitive, my pump will switch on for about 3 seconds, then off for 5 to 15 minutes depending how good condition my bag is.
The pump doesn’t work very hard at all.
Pretty easy to make,and so cheap.
Kit
hey i wish my switch was a bit more sensitve its got a 4 hg swing
btw kk
eps will deform at over 9 hg
Sorry to hijack Rickds, but you might get some benefit from this also -
Yeah, I press my skins on at 7" Hg, and only get up to around 11 when doing the rail strips.
I crank the pressure up to at least 15 in my reservoir before I connect to the bag, so when I open the valve it takes a huge inhale out of the bag and pulls it down fast.
Then I don’t need to wait, or do a vacuum cleaner pre-suck.
I have a constant-run switch that overides my vacuum switch, and I just flick that for a minute to get a good prime going, then off again.
4 Hg sounds like a hassle to work with, what switch are you using?
My pressure drops less than 1 inch before the pump kicks in, and it literally pumps for 5 seconds before it’s off again.
I’m stoked with it, I guess I must have lucked-out with the right combination of springs and stuff.
The only thing different I want it to be able to vac more than one board at a time.
Kit
I like the idea of a switch controlling the pump, will have to give it a go. The pumps I use for the boatbuilding are spec’d to run 24 hours without problems. What I tend to do is have everything set-up by the evening and leave it running over night so I can get going again first thing in the morning. However I’d rather have more control and like the pressure switch route.