Bondo vs Milliput?
- Thread starter djrazr
- Start date
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But would that styrene crack if i cut it with a dremel? I'll be cutting all the way through it
19narvik40
Sr Member
If you have a 3 inch thick piece of styrene rod, do not use the Dremel. The speed is too high and it will only melt the plastic and it welds it together behind you cut. If you have a miter box that can hold the size of rod you are using, use that for a straight cut instead. I would suggest you use sheet styrene instead. Use a compass cutter to make the appropriate sized piece to fit the hole.
What kind of plastic is the part you're trying to patch? Plastics like ABS and Styrene are relatively easy to bond to. Other plastics like nylon and polyethylene are a PITA. If you're unsure, use a brush or q tip to rub a little solvent (weld-on, acetone, lacquer thinner) on an unseen area. If it kind of softens the material and smushes it around, it's a plastic that you should be able to bond to, with either a putty or adhesive. If the solvent has no effect, you might have problems getting anything to stick.
I am inclined to agree with the advice to patch the hole with a piece of sheet plastic and then use filler putty to clean up the seam. But again, the type of plastic can have a bearing on the best approach.
Bondo is a polyester resin based material, Milliput is epoxy based. Bondo has a lightweight filler in it that makes it easier to sand.
I am inclined to agree with the advice to patch the hole with a piece of sheet plastic and then use filler putty to clean up the seam. But again, the type of plastic can have a bearing on the best approach.
Bondo is a polyester resin based material, Milliput is epoxy based. Bondo has a lightweight filler in it that makes it easier to sand.
TazMan2000
Master Member
A picture is nice, but size and material that the hole is cut into matter the most if you want an answer that will actually work.
TazMan2000
TazMan2000
It's ABS. If i fill it with something, i would need to able to cut it without it melting. From reading, styrene would melt
I do have some ABS close to it. If i cut it flush to put in the whole, what can i use to seal it? I need the seal to be strong so it doesn't crack when i sand and cut it
Appreciate your help
Without seeing the piece it's impossible to say exactly what would work best but it sounds like if you are able to fill the mass of the hole with ABS you could then fill any gaps with bondo, sand that smooth, then use automotive spot putty to fill in the fine cracks. Use wet or dry sand paper and plenty of water when sanding bondo and putty. Start with coarse 120 or 180 grit and work you way finer step by step up to 320 grit, then primer and paint.
Good luck!
Good luck!
jonpaul0151
Active Member
What I would likely do: Fill with a similar plastic to a size as close as possible. Use a backing if you can, if no backing is possible do not panic. Tape the back-side with painter's tape. Use Testor's cement or, a compatible glue/weld, on the seam first. Let dry two full days. Day three fill seam by pushing-in "Apoxie" brand putty (visit Amazon; I like the gray color Apoxie). This two part epoxy putty is extremely durable. When wet or dry it can be sculpted, drilled, even tapped for screws! Museums use Apoxie for all kinds of restoration work. It is far better than a 3M Bondo Glazing putty (soft) or any modeling putty like Squadron. Apoxie is water based, three hour set, 24 hour full cure. Compression strength is somewhere up in the 2,000-3,000 PSI range, MOE characteristics are also excellent (MOE is modulus-of-elasticity aka the ability to flex just a little without cracking). No fumes. Water clean up. However, wear disposable vinyl gloves and follow instructions on package.
Couldn't have said it better myself.
I've been using Aves for over 10 years now, in everything from seam filling to sculpting masters to sealing vacuum booth fittings.
Rogviler
Well-Known Member
God what a weird thread. Fill a hole so you can cut a hole in the space that used to have a hole? I'll dare to ask the unasked question: Why not just get a new piece of plastic and cut the correct hole in it?
I feel like there's valuable information missing from this that would make me go, "Oooooh, NOW I understand, you want to..."
-Rog
I feel like there's valuable information missing from this that would make me go, "Oooooh, NOW I understand, you want to..."
-Rog
