Wood putty-fillers

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I started an evaluation of wood putty-fillers, perhaps inappropriately, on the Hayling Hoy build thread, triggered in response to the use of paste resin with catalyst hardener Aka "Bondo"(developed for use with auto body repair). There is a version for wood, more appropriately beige colored produced by Minwax readily available at hardware stores and perhaps online. Perhaps one of the administrators could move those two posts over here where they belong.
Available in the same category are the modeling clay-like wood putties, with the clay-like colored outer resin wrapping with a hardening catalyst core. PC brand has one for "Lumber" in a beige color. Kampel WoodFil brand comes in a more generous larger offering in walnut, cherry and oak tones. They all come in plastic tubes. As long as you keep the exposed ends of the putty roll covered, the shelf life is almost infinite. As is the shelf life for the Minwax brand paste and hardener, properly sealed.
The clay roll type working time varies. The Kample WoodFil brand gives you about 30-40 minutes once a chunk is sliced off and kneaded together. A little denatured alcohol will facilitate kneading and modelling, as well as cleanup as long as it remains soft. Once cured, like the paste or "Bondo" type, It's over. There is no going back.
The Elmer's, as discussed is infinitely workable with water. The shelf life is iffy. The container MUST be sealed as airtight as possible. Keep the sealing surfaces of the top and tub clean. Not a difficult task, with water cleanup, also a little sheet of plastic wrap between the top and tub helps. If the putty does start to dry out in the tub, it can be completely revived with water, added just a little at a time and stirred thoroughly with a little popsicle stick.
The clay like stuff has good bearing strength, seals to edges and can be modelled. It has been used quite effectively in modelling early sailing warship figures and decoration. It has limited work time, is toxic and is non reversable as is the paste. These two types have superior hardness and permanence once cured, whereas the Elmer's crumbles easily and has no bearing strength. It does, however, sand more easily than the other types once dried. Clearly, they all have their drawbacks and virtues. you will find their best uses differ widely. Always use the types that cure, that is use a catalyst, in a well-ventilated area, as the vapors are highly toxic.
The water putties, like Elmer's do not cure, they dry, are nontoxic and therefore safe.
 
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Hi Peter,
I am currently using Bondo Glazing & Spot Putty on my version of Nonsuch 30. I went with this product because I am modelling a fiberglass hull and the compound needs to be extremely fine grained. This stuff can all but be polished.

It doesn't require hardener and says it only needs 15 minutes to dry. I've found that, especially for thicker spots, 8 hours works better. If you don't let it dry all the way, you'll charge your sandpaper and it will dry there and bond. One downside is that it uses organic solvent, smells like toluene. Use somewhere with good ventilation. I have put it outside before. Also, it is a little (but not a lot) harder than wood which can make sanding a little tricky in low spots before you've identified them and built them up.

If you put it on too thick, you might capture bubbles within that show up when you are sanding down and there could also be cracking. Fix by putting a thinner layer over the top after the bubbly layer has been sanded roughly to shape. It's best to build up slowly, but I think that's all fillers.

Everyone has their favorite. I like this one because it is so fine, the dust that sands off is a powder and can be sanded to a fine sheen. It also maintains good tooth for primer without being too absorbent.
 
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