Adhesive for PVC-glass in a high temp situation

Question

I am making a steam condenser for my chemistry project, as our lab is not equipped with one. The materials I am working with are a 0.5 litre glass jar (was a honey jar) and some plastic pipe I bought from a hardware store (not sure about the material, but it is see through, and labile to heat). My plan is to have 4 holes in the jar's lid : Input/Output for the gas, and another I/O for the cooling water. The steam pipe will be arranged in a spiral on the inside, a small distance apart from the walls.

However, I am concerned about the adhesion, as it may come off under the high heat, and may be not be suited for plastic-plastic or glass-plastic-joints. Thus, I am looking for advice on which glue to use for this task. If the temp. goes above 110C, then the ethanol is on fire and giving me bigger problems.

Pipe Specs : Vinyl tubing, Inner diameter 7-8mm, Thickness 1mm
Jar Specs : Soda glass, Thickness 3-4mm, Outer is 8x8cm square with rounded corners, Height 15cm

Adhesives I currently have access to are Glue Gun Sticks, M-seal(Epoxy), Feviquick(not sure if it classifies as hot glue), and Crafting glue(Fevicol).
EDIT : I am open to product recommendations, but can only order them from Amazon and such.

Note :

1. I realize this may be too much information, but I can't reply back quickly so the more you know.
2. I also realize that this may not be right Stack Exchange site for projects like these, but I wanna talk adhesives and the site says DIY.

Answer 1

I think making a strong, lasting bond between glass and PVC is actually very difficult. With the temperature changes, you need something that will be flexible / elastic enough to tolerate the uneven expansion of PVC and glass. It will have to make a vapor tight seal that holds up under pressure, and stands up to the mechanical stress involved. There may be specialty adhesives available for industrial use that would work, but it will not be easy to find.

I think you'll have more luck if you look for a fitting that makes a seal through the lid, with silicone gaskets / o rings you should be able to make a satisfactory lid, but it will be fragile, glass isn't ideal. If you could find something with a lid that isn't glass, everything will get much easier.

Answer 2

A common product known as high temperature rtv silicone may serve your requirements. 550°F continuous (almost 300°C) fits into the temperature you've noted. It is a product available via Amazon, but may also be found at automobile parts stores as high temperature gasket sealer. It's often red, although I suspect that's not universal.

Your design as described would not be subject to high pressures, much above one atmosphere, and the sealant should not dislodge unless subjected to greater pressures.

Answer 3

What type of gas are you condensing? Your question says steam, implying water, but you also mention ethanol. What pressure are the steam and cooling water running at? What's the expected condensate outlet pressure? Is this just for demonstration or will you use the condensate for something? Vinyl tubing isn't the best conductor of heat and may leach solvents when it's heated. Vinyl tubing also doesn't bond well with adhesives.

My first thought is like an old small moonshine still, with an air-cooled coil of copper tubing, soldered together. If you're running large volumes of steam & condensate and need better cooling, immerse the coil in a water bath. Whatever your cooling arrangement, put your condensate and coolant inlets at the top and outlets toward the bottom to use gravity to your advantage for drainage.

If you must use vinyl tubing, look at barbed hose fittings and hose clamps. The hose fittings are available in different sizes at most local hardware stores, seal pressure-tight with common hose clamps, and can be found with threaded connections on one side that can be fastened to the flat side or top of a cooling vessel.

If you go with copper tubing, I'll recommend soldering as your first joining method. If that's not practical, JB Weld, JB Qwik, or other metal/epoxy mix may be suitable for the high temp once cured. I once used JB Weld to fix a cast iron cauldron that was then used several times for cooking food on an open fire. IIRC, it was rated at 450 F continuous after it's completely cured.

For any adhesive, check the package, search the manufacturer's website for technical info, or even call the manufacturer to ask about use with the particular materials, temperature, pressure, etc. that you're working with.