I have used a few fillers for model projects. What do you guys use? Will Bondo filler in a tube work on plastic? It seems all the ones I have used need at least 4 applications to work and reduce the shrinkage.
I use the Bondo brand spot putty or glazing compound for almost all mine. But thick applications can shrink. I normally use at least a couple coats anyway so it doesn’t bother me. I keep the squadron putty here also but the shelf life on it is like ripe bananas. I prefer the green over the white. Is Squadron still available? I know the company closed and everything was auctioned but I dont know if anything will still get produced by a new owner? I don’t know if anyone bought it really? I had got the auction info and it was everything down to the file cabinets and chairs. Kinda sad to see. I have owned a lot of their stuff both model and publications. They had a store in Detroit for a while that was incredible to visit and see the display models.
Lots of variables in your question. However, I have engines that are going 25 years of service with no shrinkage of fissures to be seen. About 30 years ago, my go-to system began to be filling with styrene as much as possible (either a plug, or a plate underneath followed by styrene on top of the plate.) Once the styrene was shaped as needed using a chisel blade and/or files, then sandpapered, then: * 5 min any big fills. Chisel excess, file to shape, then follow up with sandpaper by sanding with 320, then 400, then 600, then finer if needed. * Any hairline joints or other fine-tuning I use ACC, again following up with the above sequence. Like I said, I have engines in service that were built in the 1990s and still no evidence of any hairline cracks/etc. It's totally different than working with any of the putty's I've tried in the past, but it works, and stays put with no shrinkage over time. THAT I like. Andre
I have used the melted styrene in glue before with mixed results--it can attack the surrounding materiel. Another trick I tried for the first time recently is baking soda in ACC. It worked pretty well although was nearly as messy as the styrene-and-glue.
I use the styrene in MEK sometimes. It makes a very strong fill for sure. I use colored sprue so I can see it to sand easy. I have also use something similar to baking powder/soda or the old micro bubbles. It is a brand called JET that is the same idea. JET is made for dental labs as filler on false teeth. Very strong as filler or to reinforce glued joints. Like Andre said, I try to fill as much as possible with styrene first before any putty goes on. Once the putty has cured I also have models that are decades old with no cracks or shrinkage. interesting topic here to me at least.
Thanks for the comments and suggestions. I've used the MEK/Plastic filler or putty, ACC and Tamiya as well as others. Right now using some squadron gray putty. I am gonna try a tube of Bondo. Ran into this on the web, might try it but looks kinda pricey. https://www.ebay.com/p/1701805759 looks interesting.
Steve, After looking a little closer I see the tubes you show are two different stages and part numbers. Do these get mixed together? Or is one best for one type of filler? I just went to an advanced auto parts store and that store had two different tubes, one had a hardener and the other said plastic steel, which might be little hot for plastics. Not a very good selection, but I didnt see anything like the ones you show.
Tom, they are both just single part fillers. I don’t know why but if you buy a big tube it says stage 2. Little tubes say stage 3. No visible difference and the both fill and sand out the same. Mystery to me
Tom and Steve, These items are part of a series of products offered by 3M. You may find the information on their website helpful. The company considers their Body Repair System a 4 step, or "stage", process with a variety of associated products. There appears to be overlap in product offerings between the stages. They indicate the following stages - Stage 1 : Prepare, Stage 2: Repair, Stage 3: Fill, Stage 4: Finish. Please see the following link https://www.3mcanada.ca/3M/en_CA/auto-repair-ca/body-repair-system/ . Hope this helps. Thanks! Mark
I bet there is not a nickels worth of difference between them, a clever marketing antic to sell 3 times as much product. LOL
Very good thread and a timely one for me. I need to get some for my use and have been leaning toward Tamiya. Steve, I nearly spat coffee at the “ripe bananas” analogy, because it’s accurate in my experience. Best Regards, Chris Abernathy Columbia, MO
OK time for a little update. I bought some of this perfect plastic putty (PPP) and I have mixed uses/results for it. It goes on very easy, and very smoothly, it does not have that stringy application effect at all, water clean up and thinning. It is very fine grain and should polish very nicely. There seems to be very little shrinkage and I put it on probably 1/8" just to see how it does. In thin applications it will dry in as little as 10 minutes. Thicker took up to a couple hours, overnight and I could not put a dent in it with my fingernail, even in the thick stuff. But be informed, this stuff will go away in a flash. Once dried will still soften with water, it is easily shaped with a Q-tip for irregular surfaces and it is probably best in small irregular applications IMHO. But I gotts a project coming up that will give it a better test for me. I wouldn't use anything more coarse, than a fine to ultra fine grit it goes away that fast in wet sanding, you can carefully wipe clean let it dry for another 10 minutes before painting or reapplying. I see best uses for Squadron, Bondo and this PPP stuff, fill the big thick, with plastic, then Bondo or similar, then finish with PPP as it is just so quick to set up, sand and is so fine.
Tom, where could I get some Bondo? I need to coat my RC boat hull with some. Is it applied with a plastic trowel type tool?
I been trying to find it too Jim, maybe Steve can tell us LOL. I looked at all the auto parts stores have have not found the tubes pictured in Steve's post. I found some that needed hardener, but don't want to get into that. I just spent an hour wet sanding my project (no pics yet), getting ready to apply a layer of Gry Sq Pty. If you find some Bondo let us know. Hate to pay $5.00 shipping on a $4.00 tube doncha know.
Huffing some Squadron putty now. Trying to get rid of those annoying stringy things that seem to come with applying a layer of that stuff. But don't try to handle/craft it too much, just more work for you in the long run. Another project I am looking at, has a tiny bit of shrinkage from using Sq putty, filler on a seam. Drives me nuts. I mean that was the whole reason I applied the putty was to hid the stinking seam, probably less than the thickness of a sheet of plain paper, but in black it stands out like a 4" seam