Panel adhesives and epoxy

[Marky_Lad]

Hi all,





I’ve got a narrowboat that requires a little work on it.. I’m in the process of replacing the windows. The openings for the windows are currently rectangular, unfortunately the windows I want have a radius corner on the bottom, which means that I’ll need to add a small piece of 5mm steel to ‘fill the gap’. Originally I thought of having this welded but there are a couple of issues with this, firstly the inside of the boat is kitted out and has a ply facia, I can’t remove this without destroying the finish around the windows, so welding would be a fire hazard. Secondly I’m a little worried about distortion of the metal if welded.

Instead, it was suggested that I use an epoxy or panel adhesive. Firstly securing a backing strip of metal to the existing structure (adhered or drilled and tapped) to act as a support, then adhering the small strip of metal over this. In addition to amending the window openings, there is a window I want to remove all together. I wasn’t sure if I could do something similar to above. Create a strip around the window that provided a support for the metal plate to sit.

My question is, does this sound feasible, would there be any disadvantages to welding and what product, if any, would be best?

Hope that makes sense,

Mark

 

[MetalMonkey]

I know nothing about boats, we have some very experienced guys on here who do, so hopefully they will chime in.
However, If it was me (and I've understood the situation correctly) then I'd suggest making up some "adapter" frames to suit your new windows with sufficient overlap to provide a flange seal against your openings.
Then I'd seal it with some sort of PU adhesive (tiger seal etc) and pop rivet or bolt them on

 

[Bullet2012]

a west systems epoxy from wessex would be my go to, but it would depend how big the “fillet” is. You could bond in some fillets as well. the use sikaflex 291i to bond in the windows

Home | WEST SYSTEM Epoxy

The home of WEST SYSTEM marine-grade epoxy resins and hardeners for boat building, boat repair, home repair, and restoration.

www.westsystem.com

 

[Agroshield]

What is the radius of the radiussed corner? Something with a 10mm fillet radius is different to something with a 100mm radius.

Perhaps you could 3D print an insert for the corner that would clip over the 5mm thickness of the material. Thin bead of sealer to retain it.

What you have to think about with any backing plate (or fronting plate as the 3DP item) is how any gasket/seal on the window interacts with it - if the groove in the gasket is made for 5mm thick material, that is what you have to provide at the corners.

 

[frank horton]

lots of panels on vehicles are bonded together.....
I haven't used epoxy but have great results with Sikaflex, using it to bond steel and glass.....
u'll need to leave it once applied for 24hr's.....
once cured it's stronger than the material bonded.....

 

[TEO]

If it were mine, I would weld but only small tacks then flap disc the tacks flush, fill with a metal based 2 part filler, sand & paint.
With the windows out to expose the opening you'll be able to slide a sheet of tin or something down the back to stop direct contact with any insulation (had it been spray foamed?) and with small tacks in the 3 or 4mm cabin sides, there'll be barely any heat anyway. Bucket of water & a sponge or a spray bottle on hand just in case. Give the tacks time to cool a bit before adding more, start with a tack on each of the outer edges & work in towards the apex of the corner.
Most of the shaping of the radius can be done before tacking in place to save grinding sparks in situ.
If there is any slight deformation a tap with the hammer will sort it.
Should be fine.

 

[TEO]

With the whole window that you're looking to blank off, you're going to have to make good inside anyway so stripping back inside doesn't seem to be such a problem.
I'm not sure how you'll be able to lose the patch on the outside, filling the void with a plate to make the side watertight again is v doable but it's quite hard to disguise a patch however it's been done. Again my preference would be welding but that's just because I've got the gear& it doesn't involve the additional work of overlapping boarders on the inside.

 

[Bullet2012]

With the whole window that you're looking to blank off

OP has not mentioned blanking off any windows, just replacing.

 

[TEO]

OP has not mentioned blanking off any windows, just replacing.

I missed it in the first read too:

In addition to amending the window openings, there is a window I want to remove all together.

 

[Bullet2012]

I missed it in the first read too:

fair enough, well spotted

 

[gaz1]

Hi all,

I’ve got a narrowboat that requires a little work on it.. I’m in the process of replacing the windows. The openings for the windows are currently rectangular, unfortunately the windows I want have a radius corner on the bottom, which means that I’ll need to add a small piece of 5mm steel to ‘fill the gap’. Originally I thought of having this welded but there are a couple of issues with this, firstly the inside of the boat is kitted out and has a ply facia, I can’t remove this without destroying the finish around the windows, so welding would be a fire hazard. Secondly I’m a little worried about distortion of the metal if welded.

Instead, it was suggested that I use an epoxy or panel adhesive. Firstly securing a backing strip of metal to the existing structure (adhered or drilled and tapped) to act as a support, then adhering the small strip of metal over this. In addition to amending the window openings, there is a window I want to remove all together. I wasn’t sure if I could do something similar to above. Create a strip around the window that provided a support for the metal plate to sit.

since you have a narrowboat why are you changing to rounded off windows in the first place

are you using double glazed windows or are they single glazed

double glazed units are better you will also find them in buses, caravans and porta cabins

for the cost of what your intending to do and be warned its expensive

a note also has to be said rounded windows are expensive to replace so really consider this if you intend to use them

as goes for blocking a window off make 2 units one for the outside and one for the inside as the outside part will bolt to the inside part as the outside part can simply be plated

 

[Barking Mat]

It needs welding, any epoxy or glue will end in rust and leaks.

That's my thoughts.

 

[Barking Mat]

Stick rectangular double glazed rectangular units in, save yourself a load of hassle.

 

[Ian X]

I don't know how big the windys are, some I saw on the Bridgewater canal are poky looking oval ones, some fairly large rectangular. Do the new windows have a bezel, an outside flange?

 

[Barking Mat]

I bet household double glazed units are cheaper than marine single glazed units.

 

[TEO]

I bet household double glazed units are cheaper than marine single glazed units.

No doubt about that, I imagine they're just standard domestic glazing with 12mm spacers & marine tacked on to make them extra spendy

 

[Barking Mat]

No doubt about that, I imagine they're just standard domestic glazing with 12mm spacers & marine tacked on to make them extra spendy

I've never seen marine double glazed windows, don't doubt they exist.

Bet they're spendy.

Not like you have heavy seas structural stresses on a canal boat.

 

[Marky_Lad]

Thanks guys,

I've currently got domestic uPVC units in at the moment. Not only do they leak as they aren't designed for narrowboat usage (they don't sit vertically as they would on a wall), but they look crap too. Cheap yes cheap looking too I've got a budget of around £5,000 for replacements, I think that should just about cover the cost of thermal break, double glazed units. In my opinion rectangular windows don't look right and if I'm spending good money on them I really want something that I'll be happy with.

I should possibly have explained in a bit more detail that where the window is to be blanked off is in the galley which has been totally stripped out. The exterior of the boat has also been taken back to bear metal so repairs aren't so much of an issue there.

 

[Ian X]

What replacement product have you set your eye on?

 

[TEO]

I've never seen marine double glazed windows, don't doubt they exist.

Bet they're spendy.

Not like you have heavy seas structural stresses on a canal boat.

I designed some centre hung windows 4-12-4 in Afromosia for a narrowboat. Slight arched top with square bottom.
More of a vanity project for me, something I'd been mulling over for my own boat & persuaded a client to fund the design time. In the end I couldn't afford to make them for myself & by the time I got to the making for the client he'd had a talking to by his partner & decided that matrimonial harmony was more important than fancy wooden windows with double glazing, those were the days when the order book was stretching off into the fast distance future