WATERPROOF interior filler?

[rafezetter]

Can anyone recommend a low odor quick(ish) drying filler that is specifically waterproof, other than car body filler / 2 part epoxy types.

I previously used the normal style, water based ready mixed filler to fill a 25mm x 15mm deep gap between window cill and window frame, but the last tenant in the room allowed a significant amount of condensation to build up and it turned that filled section to mush.

I was considering car body filler, as I've used that before to great effect, but the smell is strong and offputting.

I've been suggested plastic wood, but I have not used this and have no idea how it will react if the same issue occurs, and I'd rather not have to revisit this particular problem a third time.

I'd appreciate any advice you may be able to give

 

[gwr]

Not sure if it's a timber window and cill or upvc but if you don't want to replace the cill you could overlay the existing one with the thin upvc type that returns over the nosing. I think this would be a better option than filler,just my opinion

 

[Phil Pascoe]

Exterior Toupret is very good, the downside for your application is that it is harder than hell so needs to be tooled to a finish as it is near impossible to sand. It's a powder that's mixed with water. The interior one is excellent stuff and easier to use, but not waterproof.

 

[Eric The Viking]

That's a big gap to fill! Can you put a wooden fillet in, as well as filling it? As you know, it worked a treat on my bedroom windowsill!

I'd also try mixing white (clear) PVA in with any cellulose-based filler, such as the traditional "Polyfilla" type. You might need to experiment to get the best proportion, but PVA is waterproof once dried, and should have the same effect as the powdery waterproofing additives to cement (filling the microscopic pores between the mortar granules). It will also probably make the overall mix a bit stronger, but should still take gloss paint well once thoroughly dried.

 

[kevinlightfoot]

I would splice a piece in or do the job properly and renew the affected parts be it window board or frame,you know it makes sense to do that.Fillers are a very poor way of executing a repair of that size.

 

[cowfoot]

If it's the gap between wall and frame (rather than wood)...underfill with bonding plaster, skim over with Toupret Humi Block filler, lightly rub down then coat with BIN primer.
Then make sure that the trickle vents are working, if not install some or drill more holes in existing.

 

[RobinBHM]

If there is enough space, I would just fit a trim the whole length and cover it up.

It is quite a common position for a trim, as sometimes the internal blockwork height doesnt allow the windowboard to fit into the groove in the frame, so the windowboard is butted up and any gaps hidden by a trim.

Or get some smelly 2 pack woodfiller and have the windoe open

 

[rafezetter]

Thanks for the replies all:

It's in the rented house I share, and landlords have already rejected putting cover window boards despite my recommendation.

There used to be a 65mm trim to hide that gap originally, but they asked me to remove it last time, hence the previous fix.

It's a woodchip windowcill which has already had moisture attack it and has swelled a bit in places.

The reason for my post was I did use 2pack car body filler on a smaller windowcill gap and the tenants complained about the "chemical stink" in the hallway even though the smell wasn't much worse than you get with oil based interior paint.

Is this what you mean Phil.p? http://www.screwfix.com/p/toupret-toupr ... ller/7626h

 

[Phil Pascoe]

I suspect it is - it's a slightly different box to the one I had ... having said that mine was not that expensive, so it might be a better one. Hunt around you should be able to find smaller packs.