# Sealing the grain with car putty.



## lanwater (May 14, 2010)

During a recent trip, I saw a finisher use car putty all over a bed he was finishing.
2 days later, after it dried, he sanded it, cleaned the dust.

a couple of hours later he started spray painting.

The final product looked great. The finish was flawlessly smooth.

Anyone ever used this method?

How does the car putty hold on wood in the long run? I wood think the residual humidity in the wood might cause it to peel.


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## Dennisgrosen (Nov 14, 2009)

sound a little werd to me Ian 
since ´product´s for metl is very hard in the way it can´t move with the wood 
as I know of …....... but my only knowledge about it is becourse the former owner 
off our house had used paint on the windows that normaly is used on ships and they 
are oilbased i don´t know about the newr waterbased paints they use in the car industry today
if they are more flexiple

Dennis


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## papadan (Mar 6, 2009)

If your wood is sanded, then you can get the same kind of super smooth paint finish by just priming first and fine sanding the primer.


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## greasemonkeyredneck (Aug 14, 2010)

I have seen contractors years ago fix termite damage with car putty (bondo). They used drills, saws, and whatever they needed to remove all damage from some posts they were fixing under an old porch. Then they filled it with bondo. They let it sit a few days and then come back, sanded and painted it. 
Like you, I noticed it looked good. However, I was only there to fix the roof. I have no idea what the long term results were.


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## ScottN (Jan 24, 2011)

I've used sheet rock compound for the edge of MDF. I would put a thin layer on, forcing it into the grains with a little pressure and 2 hours later I would sand it off. Works great for painting.


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## Uncle_Salty (Dec 26, 2009)

I have used "bondo" to repair window sills and whatnot from time to time. You can adjust the drying time by varying the amount of hardener you add to the mix. Very similar to using epoxy, except bondo is a lot cheaper! But be warned: Bondo is a little "fumey." You had better be in a well ventilated area when using it.

Drywall mud is great for the edges of mdf. That is a great tip.


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## Earlextech (Jan 13, 2011)

The idea of using Bondo to fill problems areas, under a painted finish, has been around for years. I was doing it at least 30 years ago and I'm sure I wasn't the first. Also, never had any customer call with any issues related to it.


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## RobertT (Oct 14, 2010)

I have used bondo to fill grain on a painted project. Works great. The only problem I had was it cured way to fast. I am sure that was user error.


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## rance (Sep 30, 2009)

Dennis, unless you put a 'continuous layer' on, the expansion and contraction won't be a problem. Simply filling pores is generally ok.


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## CharlieM1958 (Nov 7, 2006)

As others have noted, using bondo on wood is fairly common. It's great for painted applications, but I wouldn't want to try staining it.


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## Planeman40 (Nov 3, 2010)

A while back I bought some glass-paned wood doors to be assembled to replace a wide sliding glass door. These came from a surplus place. The doors appeared to be new doors that had an error in the placement of the holes drilled for the door knob units. I used Bondo to fill in the holes and then used a belt sander to sand down the filled in areas. The doors were painted and now after seven years of use with one side exposed to the weather the filled in spots are still undetectable.

I have also used Bondo to fill in other imperfections in doors and other wood items bought from surplus suppliers and all applications have worked very well as long as you are painting over the repaired area. You can't even see the repair if it is sanded well before painting. The repair holds up well too.

Planeman


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## LeeBarker (Aug 6, 2010)

Bondo is great stuff. If it can withstand the movement of metal and extremes of temperature typical of most cars, it's good for wood. I keep it around.

The conundrum is how much to buy. Large amount is significantly cheaper by the pound, but if you don't use it, it gets, well, useless. Maybe the small size is a better buy.

Tip: If your hardener dries up and the paste is still good, drop by your local auto body supply place. A little chat and you may well walk out with a free or cheap tube of hardener alone.

Kindly,

Lee


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## Loren (May 30, 2008)

I have seen it used and used it for paint grade work and it works
very well. It doesn't seem to shrink too much. I suppose it
can be tinted darker as a grain filler, but there are other options
that involve less toxicity and are simpler to use.


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## Spoontaneous (Apr 13, 2009)

Yeah, bondo is good all around stuff. There is very similar product that I like even better. It is a stone adhesive with the trade name Akemi and they use it to fill in holes in marble and granite. They have a couple of different formulas…. the 'knife grade' which has a finer texture than the bondo and comes in transparent, white and buff color. The other is a 'flowing' grade and I don't remember if it is available in the buff color, but it is in white and transparent.

Like I said, it has a finer texture and you can pigment it any color or tint that you want. We used it for stone but also on fiberglass, acrylic, cultured marble, stone, etc. Same as the bondo you kick it off with a catalyst (paste or liquid). In any case, it sands to a fine finish and can even be polished with compounds. I made my living with that stuff for 7-8 years. Really versatile stuff.


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## SCOTSMAN (Aug 1, 2008)

I would have thought this was totally unnecessary and a waste of money and time too. I like wood as it is not plastic looking wood.


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## stevenhsieh (Jan 8, 2010)

Bondo is fine on wood for interior work, but for exterior it will crack like hel.
It is designed for metal use not wood.

Wood will flex more than metal.


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## Gene01 (Jan 5, 2009)

I was commissioned to refinish a baby grand piano that had been in a high school music room for over 20 years. It was oak stained pretty dark. The names and other graffiti carved into it made mere sanding out of the question. I Bondo-ed the whole thing and then sanded. For small pits, there's a patch compound that's thinner and easier to apply. 
After it was all sanded to 300, I shot it with black lacquer. It turned out fabulously. The client was happy. They bought a heavy quilted cover with grommets to accept a cable with pad locks. Hope they were able to preserve it for a while, anyway.


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## lanwater (May 14, 2010)

Thanks for all the info.

I tought it was very weird but I guess I was wrong.


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## michelevit (Oct 4, 2010)

I keep a can of Bondo in the shop. Its perfect for filling holes , crack and other wood imperfections. I leave it proud and hit it with a palm sander once it sets up. As long as your painting it, it should be fine. I build full size arcade cabinets and save quite a bit on plywood by using seconds or one offs which have knots of chips. Once I fill with bondo, its perfect. Don't be afraid to use it.


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## lanwater (May 14, 2010)

Thanks michelevit.

After all the info I gathered here. I am fairly sure I will try it.


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## BobTheFish (May 31, 2011)

http://www.minwax.com/wood-products/maintenance-repair/minwax-high-performance-wood-filler

pretty much the same thing. I've used it, not sure how it'll hold up, but considering it was used filling holes for veneer, and it's made for wood, it should be fine. I liked it a lot more than the typical wood filler you buy, and when it hardened, it was HARD. Honestly, I'd prefer it to any other sort of wood filler on the market, provided I wasn't trying to use it on something that looked like wood (it's grey and has no ability to match grain).

But trust me, I can't see how it's much different from bondo.

I also know someone who used it to fill in a small damage on a cherry piece. Not only was it never really noticed (it was on the back) but it's still holding up five to ten years later.


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## TopamaxSurvivor (May 2, 2008)

Bondo must be water proof and should work on exterior projects, eh? (anyone notice my Canadian accent ;-)) )


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## lanwater (May 14, 2010)

Thanks BobTheFish, I will take a look at the miniwax. I like their products.

TopamaxSurvivor: I never worked with it but it probably is from what I am reading.


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## bilbaggins (Sep 11, 2011)

Carbody fillers can be used on wood-I know quite a few guys doing guitar builds professionally that only used these body fillers to get flawless finishes after wet rubbing.

I think they are an epoxy resin based product so they should "flex" ok. Dont forget car metal expands and contracts constantly when out and about. Lead a far tougher life than wood products would be expected to unless it is a bed i guess! ahem….


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## Dark_Lightning (Nov 20, 2009)

Years ago, I built a knotty pine bookcase 8 feet tall and 9 feet wide. The crown molding had a small imperfection that I filled with almond caulk, then finished the whole thing with nitrocellulose lacquer. Unless the light hit it just right, even I couldn't see it, and I knew where it was. The color match was dead on.


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## KayBee (Jul 6, 2009)

We used bondo all the time in the commercial shops I worked in. Never heard of any complaints because of the body filler.


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## JJohnston (May 22, 2009)

I used it on the lower part of the "armor" on my potato cannon where I applied the decal. You can see the difference in the third picture: lower part, smooth and uniformly dull; upper part, still lots of uneven absorption of paint into the wood.
http://lumberjocks.com/JJohnston/blog/18686


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## mailee (Aug 13, 2011)

Same here, I often use the car body filler for my woodwork. Not sure about the Bondo bu tover here it's trade name is plastic padding and it is a polyester base which flexes well and is ideal for wood to be painted. I use it to fill in imperfections and then coat with an ac primer and top coat.


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## stnich (May 24, 2010)

I use Bondo all the time. One aspect I like about Bondo is you can control how quickly it cures by how
much hardener you add. You can tell how hot your mix is by how red the two parts mixed together are.
It doesn't work on all woods. Cedar and Bondo tend not to work well together. Works great on MDF.


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## lanwater (May 14, 2010)

Some great info! Thanks!


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## BillWhite (Jul 23, 2007)

See blackcherry's post on BLO, wood grain filler, and varnish. Post is titled "A timeless satin wipe on finish".
Bill


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## Bertha (Jan 10, 2011)

I've never used it but it just occurred to me that you could even add texture to it if you chose to.


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## lanwater (May 14, 2010)

Bill: I have seen Blackberry's post and found it to be extremely valuable. Thanks.

Berta: you are right you could do a lot of texturing. I guess it depends how you lay it on.

In all honnesty, I am still trying to get rid of brush marks when I paint. 
I have read 4 books on finishes, used retarders (latex with floetrol), sanded and resanded. 
I even tried different primers, more expensive brushes. Nothing realy worked.
I came to the conclusion that I have no experience with paint.

So, for the next few weekends I am going to be painting with brushes and airless and air spray.
I am most likely be trying bondo.


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## bobsmyuncle (Jan 12, 2011)

If you run out of hardener, or the tube leaks, or whatever, they sell large (2.75 oz) tubes of it at the big box stores. One advantage to using it is that it is white, so the resulting product is beige and not red, as with the Bondo Hardener.

I was ready to paint my cedar shed when I noted there were a couple of 2" holes courtesy of the neighborhood woodpeckers. I Bondoed them up and within half an hour was happily painting away. Still solid and sitting there, maybe 13 years later. So I don't really see any problem using them for external use?


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## TopamaxSurvivor (May 2, 2008)

Could this stuff be used to rebuild the end of a rafter that has water damage? Maybe cut the bad wood out and make a little pile 1/2 thick, 1 3/4 wide and maybe 6 inches long. shape it, paint it. Could one expect it to hold up better than wood in the weather?


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## finishingup (May 1, 2012)

I, too, have used BOndo for multiple projects, and use it as my primary product to fill grain on paint grade jobs.

My most recent experience with bondo? A buddy of mine hired me on to help him out with some Oak Cabinets, I raised my eyebrows when he told me that his client wanted to PAINT their OAK CABINETS! He asked me what my opinion was on how to get the surface of the Oak as smooth as possible, I suggested multiple times to my buddy that we use Bondo, however, it was his gig, so he decided on a wood putty filler. Now, I'm not one to suggest to anyone to even try and paint Oak finishes, but if times are rough, and you know what you're doing, use Bondo. when applying bondo to any wood surface, you want to start off with laying a thin coat of primer down. then Apply the bondo thinly with a putty knife or a flat edged razor, and be meticulous on your application, cover as much of the surface as you can being very careful not to have any excess buildup in corners and moldings. Bondo takes some time to sand, even with an orbital. I usually use 180, but have used 120 at times when being Lazy. sand the hell out of it until its as smooth as it gets to the touch. then Spray your primer, sand it again with 180, or 240, being careful not to sand through and of the corners. Blow off the dust, check it under a light to see if you can see anymore grain, and you'll be quite impressed with the your work.


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## waho6o9 (May 6, 2011)

A new Bondo product
3M 20082 Bondo Home Solutions Wood Filler, 1 Quart (US)3M is a diversified technology company serving customers and communities with innovative products and services. 3M is committed to actively contributing to sustainable development through environmental protection, social responsibility and economic progress. Bondo; Home Solutions; Wood Filler rebuilds, restores and replaces rotted or damaged sections of wood on doors, windows, fences, furniture, shutters and more.









I've used it with no complaints, it's a good product.


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## konnon6 (Jan 25, 2012)

Model makers and pattern makers use it all the time. Why because it saves time and money and sometimes is harder than the wood itself!
As for adhesiveness it sticks to darn near anything! In most cases better than that ape stuff LOL
and it can be cleaned up with acetone.
Now bondo isn't woodworking but it helps out greatly.
all my pattern seams are filled with bondo!


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