Sciencemadness Discussion Board

Need gasket/sealant suggestion for circumfrence of 5 gallon bucket for "buchner funnel"

RogueRose - 13-7-2016 at 17:57

I have a re-inforced 5 gallon bucket that has an inner lip about 2/5-.5" wide and about 5" from the bottom of the bucket. The lip circles the bucket. There is a 1/4" hose barb at the top of the inner ridge (would sit below the top bucket) and a drain at the bottom, on the opposite side of the vacuum barb which can use anything from 1/4" to 5/8" hose barbs.

What I need is some kind of sealant for the ring on the inside of the bucket (seen as the edge of the orange inner bucket). I have tried silicone and it made a real mess and I'm not sure exactly how to do it to make is flat and work correctly. I was wondering if there is some other kind of flexible putty gaskets that can be re-moled over and over - kind of like a tar/rubber type thing (silly putty or that tacky stuff used for hanging stuff on the walls without nails).

As a note, the bucket used to hold the filtrate is wider than the inner orange ring inside the bucket and the ring around the bucket is flat and level the whole way around. So when the bucket is placed in the black receiver bucket, the bottom lip rests about 1/6-1/4" from the outer wall of the bucket, basically in the middle of the ring.

Any suggestions are greatly welcome! Thanks!

**{edit} IDK what happened to the paragraph where I wrote about trying silicone around the edge. I lined the bottom edge and bottom side of the top bucket with blue painters tape and pressed it down (1 gallon jug of water in bucket) on the bead around the ring. It was supposed to set in 30 mins but after 4 hours I pulled the bucket out and 1/2 stuck to the bucket, the other half to the ring and it was still gooey in the middle (about 1/4" bead).

That Permatex stuff looks like it might do well and the suggestion for the cling/Seran wrap sounds like a good idea.

Thanks much to those who responded!

5gal1.jpg - 185kB 5gal2.jpg - 84kB 5gal3.jpg - 97kB

[Edited on 14-7-2016 by RogueRose]

Tsjerk - 14-7-2016 at 03:02

Are you applying a vacuum during filtration? If so you could maybe try to find an O-ring instead of glue as the vacuum will keep things sealed.

careysub - 14-7-2016 at 06:21

You could try an ordinary gasket putty, put first roll it up in plastic wrap and use the wrapped putty roll as your reusable sealer.

Bert - 14-7-2016 at 06:54

Get a caulk tube of blue Permatex.

http://www.all-spec.com/Catalog/Adhesives-Sealants-Tapes/Ana...

Make yourself a gasket shaped ring on a sheet of Polyethylene plastic (so you can peel it off after curing and use it elsewhere), and let it cure in the open for several hours, so it has skinned up but still has some liquid goo in the center. Place the gasket, and pull a slight vacuum to squeeze all the parts together and smoosh them into your gasket, bringing it to final shape. Check for leaks... The skinned over sealant should not stick permaently, with care, the gasket may be re-used. How I made man hole sized gaskets for obsolete steam boilers that ran as vapor systems a long time ago.

yobbo II - 14-7-2016 at 07:03


Obtain silicon sealent and apply lots where you need the seal. Then obtain some cling film (or some other very light plastic). Place the cling film on the mess of silicon and gently place your top 'funnel' or what ever you have on top. Allow the whole lot to set. The cling film can now be removed leaving (we hope) a percect fitting rugger ring.

macckone - 14-7-2016 at 07:03

Depends on the solvent. Cork wrapped in teflon plumbers tape will withstand almost anything.
other choices are silicon as bert suggested and two part epoxy. The two part epoxy is inflexible but much more solvent resistant. Various types of rubber sheeting are available for gasket material and price is the only object. You can even get viton for prices that aren't too horrible, but if money is an issue cardboard wrapped in teflon tape is a really cheap.