# exterior epoxy putties



## sensitive skin (Jul 24, 2013)

I have a lot of nail holes to fill on old but good condition clap board... I'm wondering if I should save money over something like abatron or westsystem and use Bondo Wood? Ive used Bondo general purpose on some of the house and want to change to a more flexible product, if the general purpose Bondo fails I'll let you know.

Has anyone seen Bondo Wood fail? I sort of expect it to perform as well as the others.

For prep, I will probably not go really all out and brush holes with abatron rot stabilizer before filling with epoxy putty, I mean my conscience might end up making me do this... But generally (after through sanding etc) I am 1. sinking nails and securing clap, 2 spraying and backbrushing troubleshooter oil (this should penetrate wood in and around nail holes so epoxy grabs this instead of rot), 3 epoxy filler, 4 sand filler and raised grain and fuzz from rough sanding, 5 spray second coat oil primer (because topcoats don't like to stick to epoxies), should be smooth now, 6 topcoat...

Someone convince me to go full abatron system or tell me about your experience with Bondo Wood

Finer point: prepping holes with linseed oil primer or equivalent versus rot stabilizer


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## Holland (Feb 18, 2011)

sensitive skin said:


> I have a lot of nail holes to fill on old but good condition clap board... I'm wondering if I should save money over something like abatron or westsystem and use Bondo Wood? Ive used Bondo general purpose on some of the house and want to change to a more flexible product, if the general purpose Bondo fails I'll let you know.
> 
> Has anyone seen Bondo Wood fail? I sort of expect it to perform as well as the others.
> 
> ...


Post some pictures. 


I typically avoid using hard/inflexible Body Fillers like Bondo on exterior wood, as I find that the expansion/contraction causes them to fail prematurely. If forced to, I might caulk the nail holes, but anything you put over a siding nail-head is bound to fail. 

Interesting to hear what others would do.


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## sensitive skin (Jul 24, 2013)

Holland said:


> Post some pictures.
> 
> 
> I typically avoid using hard/inflexible Body Fillers like Bondo on exterior wood, as I find that the expansion/contraction causes them to fail prematurely. If forced to, I might caulk the nail holes, but anything you put over a siding nail-head is bound to fail.
> ...



they're square nails and they're getting driven deep into the chestnut/oak walls... any clap which wiggles or flexes at all is getting screwed down. this siding is very stable, there was some 20 or 30 year old filler on some of the nails that hadn't come loose, im hoping to match or exceed that performance now.


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## sensitive skin (Jul 24, 2013)

Ehem after some more thought, I was hoping that primer would do the job of rot restorer/ hardener... I am going to switch gears and brush nail holes with hardener (either with Bondo Wood restorer or abatron 2 part liquid wood) before filling

My remaining questions are about the performance of Bondo Wood versus abatron 2 part filler or other similar products, as Bondo Wood is the cheapest and I doubt that it'll fail on substrate that has been cleaned and brushed with hardener...

This is all predicated on the nails not wiggling out if the ancient sheathing, so I drive them in and use exterior screws if the clap moves at all...

I'll post some pictures later


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## finishesbykevyn (Apr 14, 2010)

Chestnut clapboard? Wow. Bawlin. Im pretty sure most wood puddys/ epoxys are designed to be applied on bare wood. I personally dont see significance of applying wood rott stablizer.


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## sensitive skin (Jul 24, 2013)

finishesbykevyn said:


> Chestnut clapboard? Wow. Bawlin. Im pretty sure most wood puddys/ epoxys are designed to be applied on bare wood. I personally dont see significance of applying wood rott stablizer.


No the sheathing i.e. the wall (though there's a different name for it in these older houses, shiplap? I can't remember) is chestnut/oak. The clap is red cedar.

The stabilizer/restorer hardens the wood and restricts movement at the bond between epoxy and wood. Penetrating epoxies, liquids, e.g. west system, go on first, followed by the filler or putty...

I'm not dealing with much rot here, just the nail holes are oxidized and soft, I wouldn't trust them to hold shape well enough to keep the putty in place. Like I said I was just using an oil primer to penetrate, stabilize, and provide a bonding surface... But now I'm leaning towards wasting a bunch more time and brushing holes and areas to be filler-epoxied with a liquid penetrating epoxy. This afaik would be the best method.

Good chance I'll just stick w primer as my stabilizer though, it's a big house, it's not a boat, and I'm not completely insane.

I would apply filler epoxy to bare wood if it was really solid or had very clean grains exposed, the nail holes are of a slightly different nature, the inner of the nail hole the wood will be pretty soft and ****


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## sayn3ver (Jan 9, 2010)

The Bondo epoxy wood certainly smells and feels like normal Bondo to me (so does the minwax product in a suspiciously similar can)

I'd be surprised to find out if there was a difference in the products besides color.


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## Woodco (Nov 19, 2016)

sayn3ver said:


> The Bondo epoxy wood certainly smells and feels like normal Bondo to me (so does the minwax product in a suspiciously similar can)
> 
> I'd be surprised to find out if there was a difference in the products besides color.


I'd say, sandability. Real bondo takes a little more to sand down, so I like to use the home putty bondo instead, so the wood doesnt sand quicker than the bondo, leaving a lump.


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## finishesbykevyn (Apr 14, 2010)

Interesting. So you won't even see this stuff.? AKA, it is under the clapboard and most likely a vapour barrier of sorts. I honestly didnt know anyone would actually go through that much work on sheathing. If it's not going to be seen and it is requested to be done, I would just use caulking.. If I'm understanding this correctly. If not, disregard everything I'm saying
and your method sounds great.


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## sayn3ver (Jan 9, 2010)

No. It sounds like the home has tongue and groove or shiplap sheathing made of chestnut. Over that is cedar clapboard which is what he is looking to treat and fill the exposed nail holes. 

That's how i read it.


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## Mr Smith (Mar 11, 2016)

I used some wood epoxy filler a few weeks ago and it worked well. I used it to repair a large rotted hole in wood siding. It came in two small tubes that you mix together. It dried as hard as a rock and was paintable & sandable.

I bought it at Home Depot. For filling paint chip holes, etc I use exterior vinyl based spackle. Never had a callback ever. The trick is to prime before you add the spackle *and *after you sand it.


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## sensitive skin (Jul 24, 2013)

sayn3ver said:


> The Bondo epoxy wood certainly smells and feels like normal Bondo to me (so does the minwax product in a suspiciously similar can)
> 
> I'd be surprised to find out if there was a difference in the products besides color.


there are some different ingredients and some diff proportions of same ingredients. i think it would be a safe assumption that bondo wood filler is engineered to cope with wood movement. they of course recommend priming with hardener/restorer. bondo makes one, its a one-part brush on hardener instead of two-parts like abatron or westsystem...

bondo wood filler:

https://multimedia.3m.com/mws/mediawebserver?mwsId=SSSSSuUn_zu8l00xmxt1oxmGmv70k17zHvu9lxtD7SSSSSS--

bondo all purpose:

file:///home/chronos/u-29613f8f65b12a969616cf5ce709a95c2e057074/MyFiles/Downloads/Mediawebserver.pdf


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