some of us (not sure how many, har) are glider enthusiasts.
some of us are scratch building enthusiasts
well there's the rarer few that do both (like me)
anyway I've been trying to do cheap vacuum bagging
vacuum bagging is a method of adhering balsa wing skins to foam cores or getting fibreglass to stick to the foam wings using as little epoxy as possible...
biggest problem is getting a reliable vacuum pump
so here's what I managed to find...for $2.90 somewhere in Ang Mo Kio...

this is a ball pump. there are 2 ends. the pointy end is where the air comes out to inflate your soccer balls, basketballs, etc
the OTHER end has holes for the air to be sucked in
what we need is to seal up these holes with epoxy and then make ANOTHER hole for the check valve to go into.
now, you need this device called a CHECK VALVE. (for those of you dabbling in aquariums and planted tanks, you would know what I'm talking about). it only allows air to flow in 1 direction.
drill a hole in the pump and push the check valve in. make sure it's in the right direction (when pumping, you still can feel some suction). seal all gaps with epoxy or sealant.

the other end goes into a bottle cap with another check valve on top. I use aquarium tubing to connect them. There is another type of aquarium tubing, black ones that are more rigid but I used regular ones (the black ones are for CO2....for planted tanks)
and now I crush the bottle with atmospheric pressure....

a regular bottle to compare, duh
now you need a proper vacuum bag. I am fond of using the 2 dollar daiso vacuum bags for storing clothes..... they seem rather tough.
now what I did is get another bottle, saw off the neck area and put it in the vacuum bag. then using your bottle cap, screw it over once you made a hole. I'm really bad with words here, but just take a look at the picture, you would get it.
I'm still fine tuning the results but it seems you need an O ring for better results...... ah...

in this pic I'm 'bagging' a scrap piece of foam. no biggie there, I was just testing how tight was the pressure.....
note to self, do not use too big a bag.
Qn: Y U NO USE Converted Aquarium pump???
I did, but bought the wrong type. It said 'vacuum pump' but it was a 'water lifter', more for doing little fountains for terrariums...
I might use an aquarium pump, but I do not wish to risk a good $20 on something that may end up useless.....so any people willing to donate their old pumps to me are most welcome.
We can talk about our other hobby....'fishkeeping' and 'aquariums'= p
Qn: in RCgroups, there is extensive mention of 'caulking'. Where can I get it? I have not been able to find it in Singapore.
Ans: Well......this looks like what you need. Block 412A Ang mo kio hardware store. do note...it's 12.90. horrible.
go for ziploc bags instead la....
some of us are scratch building enthusiasts
well there's the rarer few that do both (like me)
anyway I've been trying to do cheap vacuum bagging
vacuum bagging is a method of adhering balsa wing skins to foam cores or getting fibreglass to stick to the foam wings using as little epoxy as possible...
biggest problem is getting a reliable vacuum pump
so here's what I managed to find...for $2.90 somewhere in Ang Mo Kio...
this is a ball pump. there are 2 ends. the pointy end is where the air comes out to inflate your soccer balls, basketballs, etc
the OTHER end has holes for the air to be sucked in
what we need is to seal up these holes with epoxy and then make ANOTHER hole for the check valve to go into.
now, you need this device called a CHECK VALVE. (for those of you dabbling in aquariums and planted tanks, you would know what I'm talking about). it only allows air to flow in 1 direction.
drill a hole in the pump and push the check valve in. make sure it's in the right direction (when pumping, you still can feel some suction). seal all gaps with epoxy or sealant.
the other end goes into a bottle cap with another check valve on top. I use aquarium tubing to connect them. There is another type of aquarium tubing, black ones that are more rigid but I used regular ones (the black ones are for CO2....for planted tanks)
and now I crush the bottle with atmospheric pressure....
a regular bottle to compare, duh
now you need a proper vacuum bag. I am fond of using the 2 dollar daiso vacuum bags for storing clothes..... they seem rather tough.
now what I did is get another bottle, saw off the neck area and put it in the vacuum bag. then using your bottle cap, screw it over once you made a hole. I'm really bad with words here, but just take a look at the picture, you would get it.
I'm still fine tuning the results but it seems you need an O ring for better results...... ah...
in this pic I'm 'bagging' a scrap piece of foam. no biggie there, I was just testing how tight was the pressure.....
note to self, do not use too big a bag.
Qn: Y U NO USE Converted Aquarium pump???
I did, but bought the wrong type. It said 'vacuum pump' but it was a 'water lifter', more for doing little fountains for terrariums...
I might use an aquarium pump, but I do not wish to risk a good $20 on something that may end up useless.....so any people willing to donate their old pumps to me are most welcome.
We can talk about our other hobby....'fishkeeping' and 'aquariums'= p
Qn: in RCgroups, there is extensive mention of 'caulking'. Where can I get it? I have not been able to find it in Singapore.
Ans: Well......this looks like what you need. Block 412A Ang mo kio hardware store. do note...it's 12.90. horrible.
go for ziploc bags instead la....





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