View Full Version : Thread sealer.

22-08-2016, 09:12 PM
Hello all,

I recently bought myself a pressure tank (this one from pressurepots.co.uk (http://www.pressurepots.co.uk/resin-casting-pressure-tanks/resin-casting-pressure-tanks/resin-molding-tank-10.html)) but disappointingly it's a leaker. I might send it back, but poking around on the net, I've got a feeling that these pots are consistently crap at holding pressure and I'll never have any joy... First off I'll try leaving it connected to my fully charged (but switched off) compressor, if it can maintain 4 bar for 24 hours using the remote tank then I guess I'll just live with it. If not I'll try re-sealing the threads on the connectors, maybe even up-grading the plastic regulator unit if that doesn't work...

Any good recommendations for thread sealer, particularly stuff that can work with metal/plastic as well as metal/metal connections...?



Clive S
22-08-2016, 11:39 PM
Wal You could try this not cheap but it works http://www.screwfix.com/p/la-co-lac-42018-pipe-thread-compound-240ml/53863#product_additional_details_container or bring it round and I will seal it for you.

23-08-2016, 12:49 AM
Hi Wal
Looking @ the setup i would think thread tape would seal those fittings.
First job is to knock up a solution of soapy water and douse it all to identify your leek. good chance it might be leaking from the joint on the cover.
Presurise the tank shut the pressure in remove the supply hose @ the valve and make sure the valves not passing.

23-08-2016, 08:48 AM
For oil pressure systems we used to buy Jet thread sealant from our local Pipe Centre, comes in a tube and sets after using I seem to remember.

23-08-2016, 12:19 PM
Cheers guys!

I've gone for a pot of that JET V2 stuff, hopefully it'll help...!


23-08-2016, 02:05 PM
Good, I look forward to all your "look what I've done" posts so looking forward to seeing what you produce with this...😀

23-08-2016, 02:31 PM
Hehe. Hopefully not a mess... I've been having a go at the cold enamelling process and want to make as good a job of it as possible, hence the tank to squeeze out them bubbles...

Here's a test piece that looks alright from a distance - I assumed the sparkle resin to be a paste and got my mixing ratios wrong and had to hurriedly mix in black paste after the pour. Loads of flaws in the epoxy, but it's got potential..!



23-08-2016, 02:43 PM
Looks good to me Wal!! Does pressure do it? I thought you vacuum degassed to pull out bubbles in things? Where do you get your cold enamel from? I fancy having a go myself :biggrin:

23-08-2016, 03:05 PM
Yep, after a bit of research I decided to go with pressure - you can de-gas your mixed epoxy prior to pouring it (and that's probably best practice) but you'll end up pouring through the bubbles that accumulate on the surface and you'll likely introduce more bubbles whilst distributing and prodding the epoxy into the harder to reach areas. I can get a pretty bubble free mix by leaving the resin/hardener standing in advance and then taking care not to 'whisk' whilst mixing - you just need to go really steady with it. By allowing the epoxy to cure under pressure, you'll hopefully squeeze down any left-over bubbles - in theory 4 BAR should give a 4x reduction in volume of a given bubble.

I bought my epoxies from Cookson Gold, you'll need:

Hardener (http://www.cooksongold.com/Enamelling/Epoxy-Resin-Hardener-250g-With-----Dispenser-Un2922-prcode-860-032E)
Resin (http://www.cooksongold.com/Enamelling/Clear-Base-Epoxy-Resin-250g-Un3082-prcode-860-032F)
Colour pastes (http://www.cooksongold.com/Enamelling/-Range=Cold_Enamel_Colours/-Type=0/&prdsearch=y)

You've also got the small quantity pearlescent effect colours - they come in pots the same size as the pastes, but they're resins and need to be mixed directly 2:1 with the hardener. In addition, a small set of digital scales and loads of latex gloves will help. Like most epoxies, it's nasty stuff so take care with it..!


Clive S
23-08-2016, 04:58 PM
Wal you can buy small syringes 2mand 10m from Coronation St. Reddish http://www.lewis-plast.co.uk/diagnostics-treatment/hypodermics/disposable-syringes near you I use them when I mix very small amounts of epoxy.

Boyan Silyavski
23-08-2016, 11:45 PM
A bit late to chime in, but normally for this job i use epoxy. My vacuum station is all sealed with epoxy, so is my compressor and mist system. If i am in doubt that will have to unscrew it later, i use the 2euro epoxy from a chinese shop. Which works well. if propane or oil is involved, i use expensive epoxy.

As a friend said once- " all you need is one hand distance aways from you, just look around, you have it"


24-08-2016, 01:28 PM
Also i think the double syringe item shown will mix the epoxy in the nozzle so no air entrainment ?

24-08-2016, 02:07 PM
>As a friend said once- " all you need is one hand distance aways from you, just look around, you have it"

That friend wasn't Eric Cantona, was it..? :biggrin:

Those double syringes are cool, but mixing the resin/hardener/colour paste requires odd quantities and furthermore they need measuring out by weight, ie. 10g of resin + 0.5g + 5g hardener. Might be worth trying a syringe to dispense into the more detailed parts, although I have a feeling that the mixture will be a little too viscous... On the smaller stuff I'm currently over-pouring and then sanding back the excess before polishing which gives a nice flush finish, but I do like the way that the epoxy 'sags' into the pockets on larger designs - you get some nice reflections.