Pop riveting windows

[blackrose]

I'm sure there are bound to be detractors but what are the disadvantages? Currently my windows are screwed in, but they're screwed through the cabin side into the hardwood linings on the inside and because of condensation in the area one has started to rot from behind and the screws have nothing to bite onto. 

 

In my view windows and internal linings should be fitted independently rather than relying on each other so I'm thinking about pop riveting the windows in. I know some people will say that's too permanent but it's not really as they only take a second to drill out.

 

What say the forum?

[Tony Brooks]

I say OK is you are sealing with an adequate thickness of closed cell foam, but if using a mastic type sealer, I would fear the rivets may squash too much out.

 

You could try rivet nuts or simply tap the cabin side and use set screws. With the window out you may find countersunk wood screws through the cabin side securing the lining framing.

[truckcab79]

Discussing this on Facebook currently as it happens as I’ve taken my first two out to restore. I think you have to make a judgement call on your own windows.  Mine will be going back in with rivets on butyl tape.  Reasoning is that the butyl is more solid and will therefore fill any larger voids more completely than uncompressed neoprene.  It it’s quite dense. You’ll have no issue with it squashing out under the pressure of a rivet. Rivet will snap long before that.

 

Profile will make a difference. My frames are slightly domed and will deform if I put too much pressure on them. Flatter profile would mean this isn’t an issue.  
 

Feedback from others that have done it is mixed but marginally more recommend butyl as the neoprene has leaked on theirs. 
 

In an ideal world I’d tap the sides and use machine screws but the holes are already there and I cant make them any bigger by threading.  Some of them are barely in the steel as it is.  If I wanted categorically to seal them and never remove them again I’d Sikaflwx them. But I won’t just in case. 
 

Rivets will be blind/sealed.  Doesn’t make a huge difference but makes sense to eliminate every place water can get in. 
 

 

Incidentally rivet nuts are great but they have a height albeit small which means you’re adding more gap if you use them.  Not advisable.  

[blackrose]

1 hour ago, Tony Brooks said:

I say OK is you are sealing with an adequate thickness of closed cell foam, but if using a mastic type sealer, I would fear the rivets may squash too much out.

 

That's a good point. Hadn't thought of that. Can you actually use neoprene foam or butyl tape on a 15" porthole or would the curve be too great?

Edited April 2 by blackrose

[GUMPY]

Pop rivets generally have steel shafts part of which remains in the rivet. Due to the position in the window they can't be painted so you get rust!

Stainless steel machine screws into the steel is the way forward.

Edited April 2 by GUMPY

[blackrose]

7 minutes ago, GUMPY said:

Pop rivets generally have steel shafts which due to the position in the window can't be painted so they rust!

 

I didn't realise, I thought they were aluminium, but of course they'd never have enough tensile strength. Can't you get pop rivets with stainless shafts?

 

Edit: https://www.boatfittings.co.uk/mobile/p/316_stainless_steel_pop_rivet_316_stainless_steel_rivet_for_marine_sailing_boat_blind_fixings?gad_source=1&gclid=Cj0KCQjw2a6wBhCVARIsABPeH1u5g18PMecl8w07sUKPD94zmWLd8H-P6uVmCUsnvaNl4FO8-OHeN84aAmaxEALw_wcB

Edited April 2 by blackrose

[Tony Brooks]

14 minutes ago, blackrose said:

 

That's a good point. Hadn't thought of that. Can you actually use neoprene foam or butyl tape on a 15" porthole or would the curve be too great?

 

If the butyl tape was what I used then yes, it would "mould" around the porthole, but despite what Truckcab says mine did squish out and continued to squish out for several months.

[GUMPY]

9 minutes ago, blackrose said:

 

I didn't realise, I thought they were aluminium, but of course they'd never have enough tensile strength. Can't you get pop rivets with stainless shafts?

Yes you can.

 

Talk to @ptolemy lane    up in the paint shop. He can advise the best way to fit and seal the portholes.

 

Edited April 2 by GUMPY
Speeling

[Tracy D'arth]

From experience rivets are too hard to pull, they squash whatever seal is used and are too permanent. Ally ones will corrode away, steel will rust, stainless take massive power to pull.

Tapping the holes for stainless round cap allen heads is the way to go.

[Ex Brummie]

Over 35 years, the pop rivets securing my windows have worked witout any troubles. 

[blackrose]

19 minutes ago, GUMPY said:

Yes you can.

 

Talk to @ptolemy lane    up in the paint shop. He can advise the best way to fit and seal the portholes.

 

 

Yes will do.

11 minutes ago, Ex Brummie said:

Over 35 years, the pop rivets securing my windows have worked witout any troubles. 

 

I've found sealed, stainless pop rivets (body & mandrel) but they're in A2-304 rather than A4-316 stainless. 

 

I'd have thought A2 is adequate for a non salty environment.

 

I'll order enough to do one porthole with a PU sealant as a test and then do the other 13 🫤

[Alan de Enfield]

14 minutes ago, blackrose said:

I'd have thought A2 is adequate for a non salty environment.

 

Thinking the same - I used some 304 set screws last September in an outdoor application, and on looking at them a couple of weeks ago, they were totally rusty ('rust-brown' all over)

 

I'd go for the proper stuff or be prepared to live with rusty 'runs' down your paintwork.

[truckcab79]

59 minutes ago, Tony Brooks said:

 

If the butyl tape was what I used then yes, it would "mould" around the porthole, but despite what Truckcab says mine did squish out and continued to squish out for several months.

Apologies for any confusion. It certainly will squeeze out but not in a messy way. It never sets so under the pressure of the fixings it’ll  continue to want to move into any void, including out from under the frame. Exactly what you want in a sealant.  What it isn’t doing  is leaving gaps and voids anywhere as it squeezes out. What squeezes out is easy to pick or roll off.  
 

As my windows are old and I uneven I’ll be using butyl. If they were flat and new I’d probably go with neoprene tape.  If I wanted them to go down, seal perfectly and never come off again without damage I’d be using Sikaflex.  You’re best placed to make this decision yourself knowing what your own windows are like. 

[BEngo]

An aluminium window frame, on a mild steel side, with gaps and water is a hard environment for any grade of stainless pop rivet.  The  set up is a natural to encourage crevice corrosion and  dissimilar metal corrosion.    Aluminium rivets with steel formers are less of a corrosion risk,  but are not perfect. 

 

The hard part with any  pop rivetted  window frame is making it pull back evenly and  tight against the sealant and stay tight.  Sides are rarely dead flat all the way round a typical window..  If there are  big gaps in places to start with, perhaps  because the builder put sheet joins through the window holes then closed cell foam tape needs lots of extra layers and butyl tape  will squeeze out so needs to be thick ish to start .  Check with a straight edge before you start and if it is noticeably not flat a  gun grade butyl may be more useful.

 

N

.

 

[GUMPY]

I used butyl tape on Parglena it never sets.

On Loddon Tol used some other type of more solid  stuff which was infinitely better.

[matty40s]

1 hour ago, blackrose said:

 

That's a good point. Hadn't thought of that. Can you actually use neoprene foam or butyl tape on a 15" porthole or would the curve be too great?

 

1 hour ago, GUMPY said:

Pop rivets generally have steel shafts part of which remains in the rivet. Due to the position in the window they can't be painted so you get rust!

Stainless steel machine screws into the steel is the way forward.

We have used 3.2.mm x 15 mm pop rivets on the latest boat, black ones as the new windows are black too. Never had a problem with the steel shaft rusting.

We always use neoprene tape to seal windows and portholes, this boat has a 14" porthole and the Wesley windows tape curves nicely , Midland Chandlers not so nicely.

Edited April 2 by matty40s

[GUMPY]

17 minutes ago, matty40s said:

We always use neoprene tape to seal windows and portholes

That's what Tol uses as well I just couldn't remember what it was.

[Tony Brooks]

30 minutes ago, GUMPY said:

That's what Tol uses as well I just couldn't remember what it was.

 

Just make sure it is closed cell foam tape.

[blackrose]

2 hours ago, Alan de Enfield said:

 

Thinking the same - I used some 304 set screws last September in an outdoor application, and on looking at them a couple of weeks ago, they were totally rusty ('rust-brown' all over)

 

I'd go for the proper stuff or be prepared to live with rusty 'runs' down your paintwork.

 

Ok, thanks & noted, but I don't think they can have been A2, or if they were they must have been very poor quality. They may discolour a bit but I've never had A2 screws go rusty.

 

1 hour ago, BEngo said:

An aluminium window frame, on a mild steel side, with gaps and water is a hard environment for any grade of stainless pop rivet.  The  set up is a natural to encourage crevice corrosion and  dissimilar metal corrosion.    Aluminium rivets with steel formers are less of a corrosion risk,  but are not perfect. 

 

I'm afraid I have to disagree with this. Dissimilar metals corrosion (galvanic corrosion) occurs when connected dissimilar metals are immersed in an electrolyte not on the topsides of a boat. I get what you're saying about gaps holding water but there are no gaps around my portholes at the moment. 

 

I have dissimilar metals screwed into mild steel all over the topsides of my boat: brass mushroom vents, aluminium cleats & generator locker and my anodised aluminium window frames which have been there for nearly 19 years held in with stainless screws. If no dissimilar metals corrosion has occurred over all that time do you really think replacing the stainless screws with stainless pop rivets is going to make any difference?

Edited April 2 by blackrose

[bizzard]

All my windows, portholes, roof vents and prism are set on cheep clear silicone and pop riveted and nothing has leaked since it was all done in 1997. One gently pull pop rivets by giving gentle pulls, releasing, and re engaging the tool travelling around for even pull ups until they snap off.

[blackrose]

1 hour ago, matty40s said:

 

We have used 3.2.mm x 15 mm pop rivets on the latest boat, black ones as the new windows are black too. Never had a problem with the steel shaft rusting.

We always use neoprene tape to seal windows and portholes, this boat has a 14" porthole and the Wesley windows tape curves nicely , Midland Chandlers not so nicely.

 

Thanks

44 minutes ago, GUMPY said:

That's what Tol uses as well I just couldn't remember what it was.

 

He also uses a Bostik PU sealant.

[Sir Nibble]

Could try aralditing nuts to the inside, with the windows out and screws to hold them in place.

[blackrose]

28 minutes ago, Sir Nibble said:

Could try aralditing nuts to the inside, with the windows out and screws to hold them in place.

 

Yes machine screws with little washers and nuts on the inside is another method - no need for araldite, I could just remove the top hopper of the porthole and attach the nut on the inside. Maybe that's the way to go? No need for pop rivets or tapping threads and the compression of the sealing medium is controlled.

Edited April 2 by blackrose

[Sir Nibble]

1 minute ago, blackrose said:

 

Yes machine screws with washers and nuts on the inside is another method - no need for araldite, I could just remove the top hopper of the porthole and attach the nut on the inside. Maybe that's the way to go? No need for pop rivets or tapping threads and the compression of the sealing medium is controlled.

Looks like the easy way to me.

[blackrose]

Just now, Sir Nibble said:

Looks like the easy way to me.

 

Could be yes...