Using Butyl (/Putty) Tape for sealant

[markstirling]

Looking on the site recommended in this thread yesterday, I thought the butyl tape sealant for external fittings looked like a good idea ( See pictures on this page ). It looks like I would be guaranteed a bed of sealant under the fitting without the fuss and mess of Sikaflex.
A few google searches later, I think the American writer was referring to putty tape rather than butyl tape. Both seem to be well used by motorhome enthusiats in the states, but I cant find any seller of putty tape over here. Perhaps we call it something different?

 

[NPMR]

Double Glazers use something similar.

We used it under perspex and it both grips and seals but we also have sikaflex round the edge to seal it and it is screwed, through the tape, so I can't tell what is keeping the water out!

 

[2Tizwoz]

'BUTYL PUTTY is based on a traditional Linseed oil formulation but incorporates a butyl rubber polymer to give improved tolerance to slight movement and vibration within the frame structure.'

Whereas Butyl Tape
'A Black synthetic rubber-based extruded strip sealant, many applications include: joining waterproofing membranes - such as DPMs, high specification roofing applications, such as sealing of roof-lights. Also suitable for sealing applications in the caravan construction industry.
Excellent adhesion to a wide range of substrates.
Highly conformable
Remains flexible throughout its service life
Good UV resistance
Easy and accurate to use with little waste and no mess
Meets NFRC sealant Category A as defined in NFRC Technical Bulletin 36
Service temperature ¹40oC to +90oC
19mm x 1.0 x 45M BLACK'

Butyl putty dries and sets like stone in the same way as standard linseed oil based putty.

 

[Evadne]

There is a butyl rubber (and other types of) tape that we call "self amalgamating tape". I've used the rubber type to make waterproof joints, but it's not perfect. I :
1) on rubber coated cable, it sticks well if you prime it. I use Cow Gum (rubber solution glue) or "Scotch Kote". Both must be allowed to dry before applying the tape.
2) on other cables (PU, etc.) it doesn't stick as well.

The "butyl tape" shown in the photos doesn't resemble this at all, it looks a bit like a mastic tape of some kind. I've used a few different types of "mastic tape" for similar purposes, but none resemble the stuff in the photos, which looks closer to a putty than a mastic. "plumbers mait" springs to mind, but personally I will still be using sikaflex.

Sika is pretty good at sticking most things to most things, and the cost is only painful at first. After ten years and it's still stuck fast, you appreciate how good it is. You can buy all sorts of silicone (and other types of) goo, the better types that approach sikaflex in performance, also approach it in cost. I'm afraid I'm now of the school that thinks "the answer is sikaflex, now what is the question?".

 

[Plevier]

I recently bought a roll of stuff called Flexiseal (or maybe Flexistrip) from a glazing company, £10 for a 19m roll, 3mm x 15mm. I've used it for bedding frameless perspex windows on the boat, seems fine but of course only time will really tell. It is a butyl strip, it's not just butyl putty as sold in tubs, you can't squeeze it down to nothing or smear it out. It just quashes and extrudes a bit when you do the screws up but they do become firm. I've wondered about using it for deck fittings.

 

[marno]

I got some of this http://www.wurth.co.uk/catalogue/pdfs/UK-CD_03_0015.pdf it's 10mm but I normally roll it down to something smaller, although they do sell smaller diameter stuff. (Disclaimer, I do work for this company and if you know anyone in the automotive industry they can get there hands on this or an equivalent)