sealing portholes??

[crosser]

hi all...

 

my brass portholes are leaking so ive removed them and cleaned them up and wondering what is the best thing to seal them with to the boat?  nothing to permanent as i want to remove them again later in the year to repaint the boat...   any ideas whats best to use?   weedhatch seal maybe?   cheers

[WotEver]

Lots of recommendations in the past on here for butyl rubber tape.

[Mad Harold]

1 minute ago, crosser said:

hi all...

 

my brass portholes are leaking so ive removed them and cleaned them up and wondering what is the best thing to seal them with to the boat?  nothing to permanent as i want to remove them again later in the year to repaint the boat...   any ideas whats best to use?   weedhatch seal maybe?   cheers

Mastic tape,or I have sealed my boat window frames to the boat with guttering mastic.Messy,but cleans up easily with white spirit.

[Graham Davis]

Do NOT use silicone!!

[Higgs]

19 minutes ago, Graham Davis said:

Do NOT use silicone!!

 

Would second that. And, silicon can make it a pig to split its seal for window removal. Worst of all, any area near silicon that will be painted must be meticulously cleaned of silicon and particles. 

 

For sealing the windows, I would go with the butyl tape. Would prefer it out of a tube, but you won't need enough to warrant buying that much, although, it does keep well in the tube.

 

 

 

Edited August 22, 2020 by Higgs

[crosser]

thanks all...   just ordered some butyl tubes so i can use it for all the windows...     thanks again for your help...

[Higgs]

5 minutes ago, crosser said:

thanks all...   just ordered some butyl tubes so i can use it for all the windows...     thanks again for your help...

 

After the butyl is squeezed out of the edges, leave for 24hrs to skin over - it will be a lot easier to remove the excess. 

 

 

Edited August 22, 2020 by Higgs

[crosser]

ok thanks for that, i would of tried cleaning it up straight away....

[Tonka]

Could use plumbers mate. Same stuff as in tube but comes in a tub

[WotEver]

20 minutes ago, crosser said:

ok thanks for that, i would of tried cleaning it up straight away....

Another tip is to not screw the window/porthole down tight initially.  Pretty tight, but not all the way.  Once the butyl has set a bit over 24 hours then do the final tighten.

[Graham Davis]

2 hours ago, crosser said:

thanks all...   just ordered some butyl tubes so i can use it for all the windows...     thanks again for your help...

Can you clarify please? Do you mean tape or tubes? Two very different things.

[dmr]

I have experimented with plumbers mait (ok, especially for small bullsey on the roof) and butyl stuff (waterproof but messy to remove and might bring some paint off)).

Current favourite method is to make gaskets out of neoprene sheet. 3 or 4mm thick is about right. Mounting bolts need doing up tight to get a seal. They will likely stick a bit so you will maybe need new ones next time you remove the portholes. If you need lots then there are companies that will cut them for you. If you cut them yourself then the self adhesive neoprene is a bit easier for marking out the shape, drawing a visible line on neoprene is tricky.

 

................Dave

[magnetman]

I used 1.5mm neoprene sheets cut to size. Worked very well. 

 

Not the self adhesive foam type but the solid type. 

 

https://www.ebay.co.uk/itm/Neoprene-Rubber-Sheet-Solid-Black-Smooth-Squares-Strips-in-all-sizes-/401891105620

 

20x20cm pieces did it for me as they are 7 inch portholes. 

Edited August 22, 2020 by magnetman

[dmr]

5 minutes ago, magnetman said:

I used 1.5mm neoprene sheets cut to size. Worked very well. 

 

Not the self adhesive foam type but the solid type. 

 

https://www.ebay.co.uk/itm/Neoprene-Rubber-Sheet-Solid-Black-Smooth-Squares-Strips-in-all-sizes-/401891105620

 

20x20cm pieces did it for me as they are 7 inch portholes. 

My portholes are bigger and there is a very slight bend on the cabin side so I reckon 4mm is about right for me, it compresses down very well. Need to tighten bolts, wait an hour, tighten some more, then again over the next couple of days. I use the neoprene foam, I got a sample of the solid but it was much too hard.

 

.............Dave

[magnetman]

Yes it would not work with any curves. 

 

The portholes I did are internally mounted on mahogany rings which I made for them as they are below the side decks on a barge so needed to be recessed to avoid breakage hazards. 

 

And they are on straight parts of the hull sides. 

[Tonka]

On 22/08/2020 at 14:19, dmr said:

My portholes are bigger and there is a very slight bend on the cabin side so I reckon 4mm is about right for me, it compresses down very well. Need to tighten bolts, wait an hour, tighten some more, then again over the next couple of days. I use the neoprene foam, I got a sample of the solid but it was much too hard.

 

.............Dave

Hi there Dave  do you have a link as to where you can buy it as I would like to use it on my 11 inch portholes. Used Butyl tape last time and as you say it is not as neat. What do you use between the glass and the brass frame.

[dmr]

2 minutes ago, Tonka said:

Hi there Dave  do you have a link as to where you can buy it as I would like to use it on my 11 inch portholes. Used Butyl tape last time and as you say it is not as neat. What do you use between the glass and the brass frame.

 

There are lots of places on eBay selling neoprene foam, just search for "neoprene foam sheet". Some is adhesive backed. In general I prefer the non adhesive and just use a few dabs of glue to hold it in place if required. The advantage of adhesive backed is that its slightly easier to mark up before cutting. Getting good marking on black foam is difficult.

 

I wanted a whole set of porthole gaskets so used a company in Birmingham to supply the foam and cut and punch the shapes,, but if you only need a few its probably much cheaper to do it yourself.

 

Do make sure that you get closed cell foam, I think open cell is also available and would not be good.

 

............Dave