Re-sealing windows

bluethunder

Hi again,

Just back from our two week trip, all went very well. I did notice that some of our windows needs a touch of work on the seals and I think i'd like to have a go at this myself. Our van is a converted Ducato with proper double glazed camper windows fitted (like the sliding ones on this page: http://www.obrienscamping.co.uk/Seitz.htm#sliding)

The seals were poorly repaired by the previous owner but there's still water getting through. Can anyone offer advice on the best method/product. I assume I need to remove as much of the old sealant as possible, probably with a blade? Then just use some silicon based product to to the seals again? Should I be taping areas off and what's the best way of ensuring a smooth finish? Any help appreciated.

Aidan_M_M

best way is to remove the window , remove all old sealer , gently "key" the surfaces with sandpaper , then re-fit with a Proper sealant , Like Wurth Bond n Seal , or SikaFlex 221 . I won't use anything else . And I never have to re-seal any I've done.... silicone mastic is only for filling gaps IMO.

bluethunder

Thanks for the tips. Is it easy enough to take the windows out? I would be a fairly general handyman type person but would never have done anything like this before. And when you say 'key' the surface, are you saying to just lightly sand it but not so much that it becomes smooth?

Aidan_M_M

depends what was used to stick them before tbh... I've never failed to remove one . cleaning off the old stuff is the worst job..

and yep , spot on re the sanding.

bluethunder

Aidan_M_M wrote: »

depends what was used to stick them before tbh... I've never failed to remove one . cleaning off the old stuff is the worst job..

and yep , spot on re the sanding.

Thanks, this is all good info. I think i'll give it a shot with one window, if I do ok then i'll do the rest over time. I looked it up on youtube and there's a video with a few yanks where they lay an adhesive strip on the body and then place the window onto that. Here:

http://www.youtube.com/watch?v=4UL1ig8gnwg

Is that also an option?

cantdecide

I think you should be able to use the clear Wurth silicone sealer and not have to key the surface. I've used clear silicone to patch up motorbike fairings!

You may probably want to use a nice white sealer rather than the industrial /not very/ clear silicone. The whites or colours have a fraction of the adhesion of the clear and they go very mucky looking quickly. You can get away with using a very tiny amount of clear and get excellent adhesion and seal thus making it the lesser of two evils, IMO. It really takes very little clear to work. You could use a ton of white and it won't seal or stick as well.

The next tip is get an old windolene bottle. Mix washing-up liquid and water maybe 20/1 and give it a good shake. Lay down a skinny bead of clear silicone along the gap. Straight away, use the washing-up liquid mix as a lubricant by spraying it along the length of silicone bead. Flatten it back by dragging your finger along the length of the bead of silicone. Then leave it to cure overnight.

If you haven't tried this before, I'd definitely give it a practise run or two. You will be surprised to see how little silicone you need.

Aidan_M_M

I use cases and cases of the dedicated white Bond n Seal . And it never fails . And sticks like sh1t to a blanket . I've never seen any "silicone" type sealer to be a permanent repair . And After haveing removed and refitted literally hundreds of windows/skylights etc , I can categorically state that the biggest cause of leaks is manufacturers appkying sealer to "shiney" surfaces , where the sealer doesn't adhere to it . Hence the need to "key" it.



re the video , yeah , it's an option , but I'm happier to use the gun sealer . That way you can "butter" the excess up to the edge , and leave a run off for water , rather than a water trap.

cantdecide

I stand by what I say. Over ten years of experience in the window business tells me it's all down to choice of sealer and we use it by the barrow-load /sparingly/.

Aidan_M_M

cantdecide wrote: »

I stand by what I say. Over ten years of experience in the window business tells me it's all down to choice of sealer and we use it by the barrow-load /sparingly/.

And I stand by what I say with over 10 years in the Camper business . What works well in houses doesn't always work well in campers , houses don't get driven down bumpy roads and have the proverbial sh1te shaken out of them . I respect your knowledge , but there must be a reason why every Camper manufacturer uses sealer like the Sika or Wurth , rather than anything like silicone mastics.

bluethunder

I'm hoping to tackle a window this weekend. I'm a bit nervous about taking a window out, mainly because i've never done it before. Can anyone recommend an online guide, preferably for fitting a Seitz window?

Also, when I take the window out and remove all the old sealant/bonder, do I just apply the Wurth or Sikaflex on its own or do I need to apply anything else? I've read elsewhere that I may need to apply a primer? I am also unsure as to whether there is a rubber part to the window, can anyone shed any light on this?

samih

Using sanitary silicone is a bad idea as it has vinegar in to stop mildew and that does not do any favours to the body of your van...

Seitz/Dometic S4 have a rubber seal "built in" under the alloy frame. The fitting instructions state that sealing them is optional. That said I did use non-setting mastic when I fitted mine.

As far as my experiences in the past few years with our home conversion non-setting Seamseal CV has been better than Tigerseal PU adhesive where long lasting seal is needed. However, maybe my downfall with PU was not keying in the paintwork as Aidan_M_M suggested.

Aidan_M_M

bluethunder wrote: »

Also, when I take the window out and remove all the old sealant/bonder, do I just apply the Wurth or Sikaflex on its own or do I need to apply anything else? I've read elsewhere that I may need to apply a primer? I am also unsure as to whether there is a rubber part to the window, can anyone shed any light on this?

The sika and Wurth don't need Primer unlike other sealers .

bluethunder

Aidan_M_M wrote: »

The sika and Wurth don't need Primer unlike other sealers .

Great, thanks. I'm hoping I get a better idea of how to do this once the window is off i.e. it'll make more sense. I assume I apply the sika liberally and once the window is pressed in, just clear the excess the leave a nice finish? How long do I have before the sika becomes stiff or unworkable??

Aidan_M_M

temperature dependant , about a half hour , and it goes on easier if warm . I normally pop a tube into the hot-press , on cold days that I'm going re-sealing.

bluethunder

I've called around to a few places in Cork and none stock Sikaflex 221. I have been recommended this and can get it in Mallow: http://www.absealants.co.uk/product_26-3-17_Soudaseal-240FC.htm

Or

I could get sikaflex 291 from a boating shop: http://www.chmarine.com/acatalog/Sikaflex_Marine_Sealants_Bonding_Deck_Caulking.html

Would either of these do the job or should I insist on 221 or Wurth Bond and Seal.

bluethunder

bluethunder wrote: »

I've called around to a few places in Cork and none stock Sikaflex 221. I have been recommended this and can get it in Mallow: http://www.absealants.co.uk/product_26-3-17_Soudaseal-240FC.htm

Or

I could get sikaflex 291 from a boating shop: http://www.chmarine.com/acatalog/Sikaflex_Marine_Sealants_Bonding_Deck_Caulking.html

Would either of these do the job or should I insist on 221 or Wurth Bond and Seal.

Crisis averted, tracked down a tube of 221.

bluethunder

Ahh! :mad: Finding it impossible to get Sikaflex 221. Thought i'd tracked it down in Cork but the tubes they had were a year out of date. I can get my hands on 291, would this do the same job?? It's available in chandlery shops.

Aidan_M_M

bluethunder wrote: »

Ahh! :mad: Finding it impossible to get Sikaflex 221. Thought i'd tracked it down in Cork but the tubes they had were a year out of date. I can get my hands on 291, would this do the same job?? It's available in chandlery shops.

TBH I don't know , I use Wurth almost exclusively now , most of the 221 I use is on car stuff where I'm using it to bond rather than depend on it to seal . Myself or my dad will be in Bantry over the weekend at the car rally if that's any good to you?

bluethunder

Thanks for the offer. I actually spoke to someone in Sika in Dublin and he said 291 is the same thing just branded for the marine market. Gonna get a tube of that.

Aidan_M_M wrote: »

TBH I don't know , I use Wurth almost exclusively now , most of the 221 I use is on car stuff where I'm using it to bond rather than depend on it to seal . Myself or my dad will be in Bantry over the weekend at the car rally if that's any good to you?

Aidan_M_M

Wurth have a retail shop in Cork too.

bluethunder

Aidan_M_M wrote: »

Wurth have a retail shop in Cork too.

Picked some up here for 8 euro. This man's a legend, can we give him a gold star or something???

Aidan_M_M

bluethunder wrote: »

Picked some up here for 8 euro. This man's a legend, can we give him a gold star or something???

who?

bluethunder

Aidan_M_M wrote: »

who?

You!

Aidan_M_M

bluethunder wrote: »

You!

oh right sorry! lol I though you meant the shop you bought the Sealer! :P

You're welcome , kind words indeed , glad to be of help.

bluethunder

Finally for a chance to finish this off over the weekend. I was quite nervous doing it but I think I nailed it. It lashed rain all last night and upon checking the van this morning everything looks fine. Thanks for all the help and advice.

Now to sort out where the leak in the roof is coming from