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Potpourri of Window Questions: Mold, Bondo, Casements

2324 Views 8 Replies 5 Participants Last post by  THW
I don't work outside a lot and don't really have a lot of selective rot remediation experience. Looking to poll the audience before I start my attack tomorrow.

1. Best recipe for cleaning/fighting mold?

The actual answer is "call a roofer to fix the improperly pitched flat roof drains". While that's en route, what's your mix for cleaning up a surface before finishing?

2. Bondo. How thick a gob of this stuff can I apply before it gets into "replace the whole piece" range? I've used it before to repair some corbels to great success, but those were pretty superficial wounds and I didn't need any more than 1/8" to 1/4" of the stuff to get back to even.
On this one I've got some pretty significant portions of rot along the bottom rails of some casement window sashes. I'd be looking at going almost 1/2" deep into the pieces before all the rot was taken care of. What say you?

3. Casement sash repair. Got a bedroom with custom Marvin casements 14" wide, many many feet high. Minimum replacement cost is 1k per window.
Bottom rail is almost completely gone, and the sill will have to be replaced too. Anyone ever replace rails on a casement to any degree of success? I've never tried but it seems like it would easily end up taking 1k worth of my time to attempt to repair, unless somebody knows something I don't.


Sounds like I should probably call a carpenter or something, huh?
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I don't work outside a lot and don't really have a lot of selective rot remediation experience. Looking to poll the audience before I start my attack tomorrow.

1. Best recipe for cleaning/fighting mold?

The actual answer is "call a roofer to fix the improperly pitched flat roof drains". While that's en route, what's your mix for cleaning up a surface before finishing?

2. Bondo. How thick a gob of this stuff can I apply before it gets into "replace the whole piece" range? I've used it before to repair some corbels to great success, but those were pretty superficial wounds and I didn't need any more than 1/8" to 1/4" of the stuff to get back to even.
On this one I've got some pretty significant portions of rot along the bottom rails of some casement window sashes. I'd be looking at going almost 1/2" deep into the pieces before all the rot was taken care of. What say you?

3. Casement sash repair. Got a bedroom with custom Marvin casements 14" wide, many many feet high. Minimum replacement cost is 1k per window.
Bottom rail is almost completely gone, and the sill will have to be replaced too. Anyone ever replace rails on a casement to any degree of success? I've never tried but it seems like it would easily end up taking 1k worth of my time to attempt to repair, unless somebody knows something I don't.


Sounds like I should probably call a carpenter or something, huh?[/QUOTE]

Cha Ching We have a winner...:thumbsup:

Yes, please call a carpenter.
I'd echo Griz on looking upstream (pun intended) to find the source (pun not intended) of the problem.
Usually I'd want to replace whatever has rot and look underneath that to see how much damage is there that isn't visible. You might find that you are in a band-aid on a bullet wound situation.
If it is rot that can be cleaned up and patched, and replacement of the entire piece isn't a viable option, look into getting Abatron. The epoxy and the filler are pricier than Bondo, but it works amazingly well. If done properly the repair will be invisible once you've repainted.
Trouble is I'm working on a home that was remodeled about 20-30 years ago into a modern, flat-roofed house but they did a very poor job of addressing drainage. All the drains are easily clogged and the roof pitches leave a lot to be desired. The house is covered in what were once very high quality Marvin wood windows. The previous home owners didn't do much in the ways of upkeep it seems and caulking and painting fell by the wayside. Add some vinyl cladding to the casings, I assume to mask the problem, and you've got yourself a whole slew of rotted bottom rails on operable and inoperable casements.
Like I mentioned above, very expensive replacements, very nice people who I'm really trying to hook up here. Trying to stave off window replacement for as long as possible as there doesn't seem to be any water intrusion at all beyond the bottom rails. Interior jambs are clad and are holding up just fine except for the mold issue which I'm sure a little bleach and soap will handle.

Oy vey.
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I've always pulled the casements to do those repairs. Yes, you can completely rebuild them, and no, I can't tell you how long it will take YOU to do it:laughing: Depending on the exact situation, I'd be charging between $250 and $500, a lot of it for deinstalling, opening prep, and reinstalling.

If you can find an on-line diagram of how they're constructed, it will help you get it apart. Or better yet, find a junk one some where and take it apart for practice.
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Construction is pretty simple actually. Looks very doable. I had this nightmare situation in my first year as a helper where I was in charge of repairing 30 Pella casements from the early 80s. Nightmare. Expensive. Frustrating. That company has the absolute worst customer service and rudest showroom personnel I've ever had the displeasure of encountering. Never again.
The silver lining is that I know casement window construction like the back of my hand. Leads me to believe that my shop set up(my apartment) is not conducive to rebuilding.

That's really the second phase of the job which hasn't been bid yet. I gotta focus on this mold/rot fiasco first. I'm really trying to tread lightly as the price for this remediation is already signed off on and I tend to be a "picker" completely unable to let stuff like this go without wasting all of my time on it.
Back to the rot. You can stop it from rotting by brushing on ethylene glycol. If you want protection against insects as well, use Timbor.

No joke, you just brush on auto antifreeze (ethylene glycol) and let it soak in while you're doing other things, even without taking any of the rot out. Keep hitting it periodically to get it saturated. You can do this in place before you even touch the windows / whatever. That kills off all the rot - any wood soak with glycol won't rot.

Epoxy based products will bond to glycol treated wood, but I don't know about Bondo. I do know that Bondo tends to break it's bond with the wood over time, due to the difference in expansion / contraction. You can put a couple nails in the repair area to help keep the patch lined up if it starts working loose. The boat guys (at least some of them) will first brush epoxy on the repair area, then mix epoxy and saw dust as a filler.
So many poor decisions were made during the remodel of this place. It's almost as though caulk was relied upon as the first and last line of defense. Stucco right up against wood. Wood right up against stone. No drainage anywhere. Terrible pitches everywhere.

I finished replacing all my sills/mullions yesterday and got some of the existing stuff primed before it rained on me yesterday. Going to try to kill the painting portion of this thing today. After this is done I'm going to suggest doing an epoxy/abatron experiment on one of their windows to see if I can save them. For whatever reason I'm extremely skeptical that it will work. The one sill I replaced was so rotted and pulpy I dug it out with my pinky in one swipe. Still damp and it hadn't rained in a week. I really just don't see epoxy being able to help though no matter how many reinforcement rods I put in it.
I guess we'll see.
I'll post some before and afters once I take the afters.
I would just call Superseal, that guy will fix what's there and fix the water issues at the same time. He'll also give us pictures.

Hell I bet if you look through all his threads you can find a tutorial for what you want to do.
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