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Category Archives: How to make an inexpensive Vacuum Bagger out of an Aquarium Air Pump
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- Aquarium air pump Coffee Can Caulking Air line
This system and tutorial is designed for the beginner, but has a valuable place in the arsenal of tools of the professional builder as well. At least two professional kit builders have asked for this after sharing with them how they can provide vacuum bagged wings more easily and faster than with a single more expensive vacuum bagging system… As a comparison: My “professional” vacuum pump is a multi-cabon graphite rotary vaned monster pulling 29 inches of Mercury at 11cu ft/min… It will crush a gallon paint can in seconds! For most hobby applications, you just don’t need that kind of power or need to pay between $600 and $1,800 (USD) for a pump like that.To start, I’m putting together a “parts list” for the vacuum bagging system from pump construction to the actual bag (Hopefully, this will give you time to accumulate everything and provide me with a couple more days of rest to recuperate.)(Please note: I have always used TWO of these independent systems on the same bag as a back up… not necessary, but sure helps me sleep at night knowing there is a redundant system sucking air out of the bag containing my expensive skinned foam core! The parts list will be enough to construct two independent systems!
Pumps:
I purchased these at Wal-Mart for around $6USD… I’ve seen these go for under $1 at rummage sales! I’ve seen “Silent Giant” pumps go for $12 to $29 and do not believe they are any better… in fact, I think I had problems getting them apart to use the pump inside… Just make sure that whatever pump you obtain, fits into the coffee can or paint can you are using. (One pump per single system.)
Cans:
A simple coffee can, or a paint can works fine… In this case, I’m using both and they are both 1qt size variety. (One can per single system)
Pump Base:
These are the square wood pieces under each can… anything like this will work… it just has to be big enough to support the can with a little lip around it… One of these is ½” thick Medium Density Fiberboard (MDF), the other is ¾” thick scrap plywood; both cut roughly 6” square. If you are using a melamine or Formica covered piece of wood, we’ll be scuffing it up real well to support gluing the cans on to them (later). (One base per single system)
Vinyl Tubing:
I purchased a 20’ roll of ¼” clear vinyl tubing that matches the nipple on the aquarium pump… You’ll also see in the photo a 25’ roll of ¼” polyethylene tubing… the clear vinyl works fine, I wanted to try using the polyethylene thinking it might be better… (We’ll find out!) (20’ is enough for two systems!)
Brass Tubing:
Just a foot in length is enough for two systems. 3/16” brass K&S tubing fits the inside diameter of both the vinyl and polyethylene tubing.
5 Minute Epox:
Any brand will do… This epoxy will be used for pump construction, NOT for gluing your skins to your cores!
Wire Rod:
.045” to .062” (1/16”) diameter music wire (K&S brand sold in 36” length works fine, thin wire coat hanger will also work!) This will be placed inside the flexible tubing to keep it straight once placed in the vacuum bag. (One rod per single system. lengths should match the core your are bagging. In the case of the Telos, 24″ length is fine.)
Vacuum Bag Plastic:
Here’s where you could try all sorts of whatever is available… I have used 6mil painter’s plastic as well as 10mil polypropylene… I’d stay way from the 2 and 4 mil plastic… too fragile and it tends to wrinkle and fold up on itself under pressure (vacuum). While researching for this tutorial, I found some 10 mill clear vinyl used for window covering… This looks like it will end up being my favorite!) Right along side was a rigid clear plastic that looked much more like Mylar or Polycarbonate… DO NOT USE IT! You want the plastic to be fairly flexible; capable of contouring easily around whatever shape you will be vacuum bagging! The 10mil clear vinyl was about $1.75 per linear foot that measured 4’ across! Allow for 18” to 24” more in width of your chord and span of the wing core you will be bagging when the bag is folded over like a file folder. (Example: 24″ core length X 12″ chord width = 24″ long x 24″ wide PLUS 18″ to 24″ equals a final size of 48″X 36″ (You can always trim it, you can’t always add length!It’s cheap stuff, you’ll want to make more bags later!)
Rope Caulk Weather Stripping.
This is a clay like material is formed in a roll and used to place along leaky windows… I found this one at Ace Hardware (Lowes and Home Depot had their own brands, same stuff). Ace Hardware salespeople had a hard time understanding what I was looking for but were very patient and figured it out right away. Both Lowes and Home Depot reps claimed they didn’t have it…! At Lowes, I found a knowledgeable salesman that helped me find it! He should be promoted to the “managerial” positions that were currently filled by the people saying “We don’t carry that”… Lesson: Don’t give up! Be flexible in what you are asking for, tell them you may not be using the right words… This stuff was found near the windows department and the foam sticky back rubber window sealing strips available in rolls… You want the CLAY-LIKE stuff! I took some photos of the correct item in the store (that claimed not to carry it! Lol!) The smaller package contained 30 feet which is enough to make MANY bags! ($3USD?) Available in different colors, color doesn’t matter!)
Silicone Sealant:
I’ve put these systems together before without this stuff! Consider it a redundant back up if you’re willing to try it… I will be using this as I plan to use these systems over and over again as I return to my passion for building and flying RC aircraft.
Packaging Tape:
I included a photo of the “dispensing gun” this tape is usually associated with… The thicker, the stronger, the better… I’d stay away from the thin stuff some people use to cover their foam flying wings… It’s probably fine, but I’d prefer the thicker stuff… maybe the actual 3-M brand?
OK… I think that’s it!
In the next installment, we will begin construction of the “vacuum pump”.
Welcome to the “build”!
Radio Control (RC) gliders (aka sailplanes)
Relaxing or exhilarating -your choice!
RC gliders, also known as sailplanes, can offer the beginner a very gentle introduction to the radio control flying hobby, but can also offer the experienced rc pilot some truly exhilarating aerobatic and racing opportunities – such is the diversity
