Bonding portholes

[Guest]

Anyone got any experience getting a good bond on glass to porthole.

 

is it just one bead, or is glass sandwiched between sealer and frame?

 

im using bond-it HA6

 

[Capt Ahab]

I just bond mine in with a single bead of some heavy duty silicone adhesive between the glass and the brass.

[Chewbacka]

21 minutes ago, Capt Ahab said:

I just bond mine in with a single bead of some heavy duty silicone adhesive between the glass and the brass.

Getting an organic adhesive (polyurethane is typically used for bonding windscreens in cars) to stick to a smooth glossy glassy surface really needs an activator/primer for a long life bond.  If you don’t use the activator/primer then you will get a good bond for a few years and then it will get progressively weaker.  

 

Having done some work with a car sunroof manufacturer I would recommend a pu system including the activator/primer if you want more than 10 years life.

The glass primer is not the same as the metal primer, they do different jobs, and you do need both for the best bond.

Edited July 6, 2019 by Chewbacka

[Arthur Marshall]

I've just put a couple of small ones in with a rubber washer each side of the glass and up against the frame. Used a bit of sikaflex on the back of the brass. Be interesting to see how they get on. 

[Capt Ahab]

I inherited the two in the butty which I recently removed to have them machine polished. When they came out they were stuck in with silicone, one stuck to the frame and the other to the cabin side. If I need to address them again in a few years I guess thats ok - I removed them hanging over the side and was mostly worried about dropping them, or the screws, into the Thames!

[ditchcrawler]

24 minutes ago, Chewbacka said:

Getting an organic adhesive (polyurethane is typically used for bonding windscreens in cars) to stick to a smooth glossy glassy surface really needs an activator/primer for a long life bond.  If you don’t use the activator/primer then you will get a good bond for a few years and then it will get progressively weaker.  

 

Having done some work with a car sunroof manufacturer I would recommend a pu system including the activator/primer if you want more than 10 years life.

The glass primer is not the same as the metal primer, they do different jobs, and you do need both for the best bond.

Shit, my portholes have been in for 18 years so I am living on borrowed time

Edited July 6, 2019 by ditchcrawler

[Capt Ahab]

Arn't we all on borrowed time???????

 

[Guest]

30 minutes ago, Chewbacka said:

 

The glass primer is not the same as the metal primer, they do different jobs, and you do need both for the best bond.

can you recommend any products off the shelf?

 

I was going to use Bond-it HA6, but tested it on my pigeon holes and it seemed quite rubbery.

So instead may use the old faithful starchem pu sealer - I remember it being a bit harder..

https://www.amazon.co.uk/QPaints-PPUB-Starchem-Sealer-Black/dp/B00B4WQ1TM

 

 

Edited July 6, 2019 by Guest

[Guest]

Although Sikaflex 291i may be a good option too.

Edited July 6, 2019 by Guest

[Chewbacka]

1 hour ago, Charles_Graham said:

can you recommend any products off the shelf?

 

I was going to use Bond-it HA6, but tested it on my pigeon holes and it seemed quite rubbery.

So instead may use the old faithful starchem pu sealer - I remember it being a bit harder..

https://www.amazon.co.uk/QPaints-PPUB-Starchem-Sealer-Black/dp/B00B4WQ1TM

 

 

The stuff I worked with was teroson but it does not seem to be available to the diy market - it came in 200l drums, though I think some of the roadside repairs use it in cartridges but not found it on amazon or eBay.

So failing that I would look for ‘windscreen fitting kit’ on amazon

[MtB]

 

I recommend using either 'gloop' or 'jollup'. Both work very well in my experience. 

 

Hope that helps....

 

 

[WotEver]

7 hours ago, Mike the Boilerman said:

 

I recommend using either 'gloop' or 'jollup'. Both work very well in my experience. 

Yes, they’re far more effective than gunge. 

[blackrose]

https://www.amazon.co.uk/Everbuild-StixAll-Crystal-Clear-137699/dp/B00R36PRLQ

 

[Jen-in-Wellies]

Not done this, so no idea if it would work. Would an appropriate size U section rubber seal around the glass work?

Jen

[Guest]

Sikaflex 295Uv is the one for those interested.

Sikaflex 296 is a more expensive industrial version of this.

[cuthound]

This topic reminds me of when the Wiring Regs changed to include equipotential bonding of exteraneous metalwork.

 

I went to one job and was somewhat surprised to see the electrician had carefully connected every aluminium window frame to the central heating pipework with green & yellow cable ?

[Guest]

49 minutes ago, cuthound said:

This topic reminds me of when the Wiring Regs changed to include equipotential bonding of exteraneous metalwork.

 

I went to one job and was somewhat surprised to see the electrician had carefully connected every aluminium window frame to the central heating pipework with green & yellow cable ?

sorry what?

[WotEver]

58 minutes ago, cuthound said:

This topic reminds me of when the Wiring Regs changed to include equipotential bonding of exteraneous metalwork.

 

I went to one job and was somewhat surprised to see the electrician had carefully connected every aluminium window frame to the central heating pipework with green & yellow cable ?

But that’s how silly the regs were for a while, or at least the interpretation of them. Theatres had their house sparks running cables to all of the metal handrails between the seats...

[cuthound]

2 minutes ago, Charles_Graham said:

sorry what?

 

When installing electrical installations in accordance with the IET Wìring Regulations, AKA B.S. 7671, you are required to electrically bond all metalwork that could potentially become live in the event of a fault. 

 

In the anecdote I gave the electrician bonded aluminium window frames, which not being connected to anything electrical, couldn't become live.

 

 

[cuthound]

47 minutes ago, WotEver said:

But that’s how silly the regs were for a while, or at least the interpretation of them. Theatres had their house sparks running cables to all of the metal handrails between the seats...

 

Yes, it was the interpretation that many people applied. They quickly changed the guidance notes to clarify exactly what should and shouldn't be bonded.