Vacuum pumps...

> 10 years ago
Reply
Register to post, see what you've read, and subscribe to topics.
Harrow
Harrow
NSW
4521 posts
NSW, 4521 posts
20 Mar 2006 12:36pm
I forgot to tighten up the bung on Saturday

Fortunately it was not a hot day, and I remembered fairly quickly. My board now weighs 6.85kg, but it was only 6.8kg when I bought it, so I've got 50ml of water in it. I guess things could have been much worse.

Still, I want to vacuum as much out as I can. Has anyone got a vacuum pump that they'd be happy to lend/hire me for a few days (southern Sydney), or else any good ideas on how to get a vacuum?

Also, what would be a safe vacuum to pull without damaging the board?

Thanks,
Harrow.
CJW
CJW
NSW
1731 posts
CJW CJW
NSW, 1731 posts
20 Mar 2006 12:59pm
The only time I ever undo the bungs on my boards is if they are going on an aeroplane, or maybe sitting over winter(rarely).

Did it look like any moisture actually got in? The extra 50g of weight could have been from damp straps.

Regarding applying a vacuume to the board, i'm not sure how effective it would actually be without another inlet for the air. You would certainly have to cycle it, IE: apply a vacuume up to a certain amount, then stop the pump and let the air permiate the board again. I don't think it would be that effective, however I don't have that much experience with this stuff.
Harrow
Harrow
NSW
4521 posts
NSW, 4521 posts
20 Mar 2006 2:21pm
CJW,

You raise an interesting point. Should the bung be undone everytime? You always run the risk of forgetting like I did, or of moisture entering the board due to humidity. I guess if the board is kept somewhere cool at home, and carried on the car in one of those reflective bags, then maybe best to only undue the bung when leaving the board in a lcoked up car?

I wonder what everyone else does?
Combs
Combs
WA
152 posts
WA, 152 posts
20 Mar 2006 1:47pm
I always release the bung. That way my routine always includes doing it up. I always do it when I fit the mast foot (tighten bung, install mast foot).
CJW
CJW
NSW
1731 posts
CJW CJW
NSW, 1731 posts
20 Mar 2006 5:20pm
I've always taken the attitude that I'll do more damage to the board that one time I forget to tighten the bung rather than leaving it done up for 6 months. My boards always travel in bags (reflective) and if they are wet, which they usually are, I take the boards out to dry when i get home; leave them on racks in the garage. I've never had any problems.
Harrow
Harrow
NSW
4521 posts
NSW, 4521 posts
20 Mar 2006 5:38pm
quote:
Originally posted by Combs

I always release the bung. That way my routine always includes doing it up. I always do it when I fit the mast foot (tighten bung, install mast foot).


Yep, that's definitely my new rule. "Mast foot not allowed in track unless bung already done up." No more of this, "oh, I'll go back to the car and get my screwdriver in a minute".
waveslayer
waveslayer
WA
11 posts
WA, 11 posts
20 Mar 2006 4:42pm
As per the board lady
boardlady.com/
You should always use your vent plug daily !
She repairs a lot of boards and gives a good explanation why.
hoop
hoop
1979 posts
1979 posts
20 Mar 2006 5:14pm
I've tried vaccuming water out of a board before and it didn't work at all. I put the hose on the nose of the board (thats where the water got in ) and cranked up as much pressure as it could get and left it for 24 hours. Not a friggin drop of water came out. You'd be better of getting hold of a spinner and getting rid of it that way.
Good luck.
decrepit
decrepit
WA
12885 posts
WA, 12885 posts
20 Mar 2006 7:14pm
A couple of days ago on the vent plug post, I mentoined buying a crook one for a mini mal I made, had a mould seam thru the middle of the sealing surface. First time I tookit out soaked up a lot of water.
My method was as CJW suggested, didn't want to drill another hole in my brand new board!
Made sure the plug was as close to the lowest point as I could get it, so gravity could help the process along. Pumped it down to about half an atmosphere, (about the most vacuum that's safe), when the water stopped coming theu, let vacuum off slowly, don't want to blow the water too far back into board. Left for a while so gravity could do it's thing, then pumped down again, think I got about 100 mls out, then it stopped. My scales aren't very exact so I can't be sure if all of it is out, but it's very close.
Haircut
Haircut
QLD
6491 posts
QLD, 6491 posts
20 Mar 2006 9:25pm
been there many times with cracked board parts

take plug out and leave out in hot sun with vent plug downward and paper towel pushed into hole. As u r probably aware, this works best if board is cold to begin with. Works very quickly as a day in sun removes several mls of water. Do it asap before water spreads itself further into foam away from plug area. I bought some black plastic to lay on board to speed up heating.

good luck
Harrow
Harrow
NSW
4521 posts
NSW, 4521 posts
20 Mar 2006 11:22pm
Got myself an old laboratory vacuum pump, capable of 0.004 atmosphere.

Board lady talks about hearing the water 'gurgle'. For this to happen she must be reducing the pressure to the point that it 'boils'.

At 40 deg C this requires reducing to 0.07 atmosphere, and to get boiling at 25 deg C requires 0.03 atmosphere. This sounds a bit scary. Decrepit, where do you get your 0.5 atmosphere as being the safe limit?

I figure that I weigh about 150 pounds, and that if I stand on the ball of one foot, that is about 15 sq inches, so that is 10 psi pressure. That would be less than 0.3 atmosphere.

Since the water went in the bung hole, I guess it should come out much easier than if it entered a crack a long way from the bung. I'll take it easy and see what I can get out. Will post my results.

Regards,
Harrow.
decrepit
decrepit
WA
12885 posts
WA, 12885 posts
20 Mar 2006 8:43pm
Harrow, Practical experience I guess, over .5 low density foam starts to compress. Sure the stiffness of the outside skin offers a lot of resistance, and you may get away with a whole atmosphere, but if I had a nice new board I wouldn't be taking the chance!!!
it's not the psi you have to worry about, the stiffness of the foam sandwich, spreads your weight over a big area of foam, it's the total pressure over the whole surface area, that's the problem. I'll let you do the maths, but I think .5 atmosphere works out to be quite high.

I like the black plastic idea, that could get the board up to 50-60C, Still wouldn't boil, but should help the vacuum process.
Not sure if the gurgling noise is thru boiling, may just be air and water coming out together
Waiting4wind
Waiting4wind
NSW
1871 posts
NSW, 1871 posts
21 Mar 2006 12:17am
I can't imagine you would have gotten much water in their with that weight diffrence, given the tolerance is +- 6%. Leave the board in your car on a hot day. If there is water in, particularly one thats entered through the bung, it should start to bubble out.

I never take my bung out cause I know I'll forget. I've never had a problem with a production board leaving the bung in.
Harrow
Harrow
NSW
4521 posts
NSW, 4521 posts
21 Mar 2006 1:25pm
Thanks for all the comments and suggestions. I'll stick it in the car, and go very easy on the vacuum, say lower it to about 0.75 atmosphere. Forget the boiling theory, (waaay too risky), the flow of air through the foam voids should be enough to bring any water back into the bung hole cavity. If nothing comes out, then it's probably safe to say there's virtually nothing left in there.

backloop
backloop
QLD
141 posts
QLD, 141 posts
26 Mar 2006 9:06pm
that with the papertowel works fine. put the hole must be up because steam rises. down just for real hard cases to let water drip out first. to vacuum it i used a pump from a kiter. reverse of corse. the most handpumps (for dinghys ...) can be used reverse.
good luck.
snides8
snides8
WA
1731 posts
WA, 1731 posts
26 Mar 2006 9:03pm
Harrow,
haven't seen it mentioned yet but one of the best (cheapest) vac pumps available is an old fridge compressor (look for council pick ups! always heaps on the side of the road) when you have one,(after reclaiming the refrigerant in an enviromentally fashion), plug it in and determine which copper pipe sucks and which one blows (stay with me on this! ;)) attach suck end to board pref vent hole, drill a hole in the end of the board and start sucking (turn the compressor on i mean) good idea is to put in a water trap in between the board attachment and the compressor (this can be a vegemite jar depending on how much water is in the board; ps- it is a good idea when you first purchase a board to establish a base weight, this enables a quick check to determine if there is water in the board i.e. 1kg = 1 litre of water; with 2 holes drilled in the top and a piece of tube from the board in one hole and the tube to the compressor in the other) the open hole at the end of the board allows for air to pass through the board and hopefully dry the board at the same time,it helps if the enviroment is hot and low humidity.
another addition to this (which i havent yet tried, is to add a jar of "damp rid" to the equation- place a jar at the open end as a type of trap, again, (like the water trap) this should allow 'damp rid' infused air to be drawn through the board, hopefully helping in the drying process. i would probably leave the compressor going for some time even several days or untill destruction of the compressor!
failing- that chuck the board away!
snides8
snides8
WA
1731 posts
WA, 1731 posts
26 Mar 2006 9:09pm
p.s- if it was a hot day, you may not have got a drop in the board, as the expanding air within the board would of helped to keep the water out!(but not for long!)
waveslayer
waveslayer
WA
11 posts
WA, 11 posts
27 Mar 2006 11:28am
50 mls of water, mate let it go! think about it EPS is like a maze/honeycomb of spaces It's like one of those puzzles that has ballbearings in a maze, as you move it around some of the ballbearings go were you want and others go the other way.
Harrow
Harrow
NSW
4521 posts
NSW, 4521 posts
27 Mar 2006 2:53pm
I used to be addicted to those puzzles - couldn't stop until I'd got them out.

That's it, now I won't be satifisfied until I get all 50ml of water out. Anything less would be like getting 49 balls out of 50 in the right spot in the puzzle.
Please Register, or first...
Topics Subscribe Reply