I’m using Testors Liquid Plastic Cement to join acrylic parts. My LHS had Tenax but said Testors is just as good. I find it bonds, and the bonds appear to be strong, but I must hold the joint for some 30 seconds or so before the pieces fuse. I’m applying the cement with the brush in the cap.
This behavior is not nearly as aggressive as I’ve experienced with WeldOn #16 on styrene, for example.
Is this expected behavior or should I use Tenax instead?
Rick Krall
Proweld from Ambroid is the best with Tenax 7 a close second and an acceptable replacement. Most others you can toss in the trash as far as I’m concerned!
Looking at the product pictures on the internet, I see that the ProWeld bottle states that it can be used for acrylic material. I didn’t see this on the testors product.
Looking at the Plastruct website, http://www.plastruct.com/picat/F.Y.I_9.pdf, it appears that they sell three different types of liquid cement: one is for styrene only; one is for joining like plastic materials; and one is for dissimilar plastic materials.
So are you joining acrylic to acrylic, or some other type of plastic to acrylic?
A great question, Maxman, and I should have specified: I’m joining acrylic to acrylic. You’re right–the Testors website doesn’t provide any info, but the Tower Hobbies site advises it’s suitable for Plexiglas, which appears to be a trade name for clear acrylic. So I conclude I’m in the right ballpark but that a specialized product might offer a shorter setup time and less chance of misalignment while waiting.
(Great link, BTW; thanks.)
Rick Krall
Not to beat this to death, but I’d not heard of ProWeld and was curious about plastic welding in general and so poked around a bit. I found this thread from Fine Scale Modeler that discusses the mainline products:
http://cs.finescale.com/FSMCS/forums/p/88726/907492.aspx
One poster noted Testors’ slow bond time, which matches my experience.
Rick Krall
I use small paint brushes to apply liquid cements as the brushes on the lids are too big. They may harden up but when I put them back in the cement they soften up.
I made the mistake once of buying the Plastruct glue, didn’t work well at all and no I didn’t buy the wrong one as I checked.
Acrylic or Plexiglas or Lucite are all the same material, Methyl Methacrylate. The best solvent cement I have found is called WELD-ON #3, made by IPS Corp. It is available at commercial plastic suppliers (check your yellow pages). Although it is specificaly made for acrylic, I use this for styrene and even some ABS materials. It bonds almost instantly but should be allowed to set for 15-30 seconds before releasing the parts. With styrene kits, I use a small brush to flow it into the joints or seams from the back side. It will leave a slight solvent etched surface, so if it is on a finished surface that is not going to be painted, always apply from the back side. this is sold in pints and quarts and gallons, but is expensive ($10.00 for the pint). A pint lasts me a long time, 6 months to a year.
Bob
I gave up on the modeling liquid cement, and went to using MEK (Methyl Ethyl Ketone). I can buy a 3 quart cans for what one of those little bottles cost. I just refill the bottle with a funnel. I’ve had a can for almost 2 years, and haven’t hardly begun to empty the can, yet.
Perhaps one of us with some substantial knowledge of plastics adhesives could provide more definitive information on the various brands and formulations of model glues- a comparison across plastic compounds and across glue/adhesive brands. This sort of comparison, using sets of specific pairs of bonding materials has been done in several woodworking magazines for carpentry and woodworking glues. Application and circumstantial use preferences generally follow the evaluations for when to use and where to use, etc.
I use the Testor’s Model Master brand- the black container with the needle applicator- and find it flows more precisely because of the needle applicator, requires a 15-30 second initial contact time and bonds styrene to styrene, as well as styrene to ABS (some Plastruct modeling materials are the more durable/stronger ABS variety).
I also use Testors Liquid Cement (brush applicator) and the Testors Clear Parts Cement. I would be cautious about using industrial-strength solvents (MEK, etc.) inside a house (irrespective of “adequate ventilation”) due to their more noxious odors and proximity to pets, children, wives, etc.
Boy; the gift that keeps on giving. Thanks, guys, for the continued contributions. Cedarwoodron–I think your comparison idea is a good one.
I’m building a CMR turntable, hence my original question. I’m inserting the pit rail ties, all 198 of them. There’s a bit of play in the slot, and CMR recommends pushing the tie towards the front of the slot to assure perfect alignment. That’s why the 30-second hang time can be problematic–if I don’t remain perfectly still, the tie can slip out of alignment as it bonds.
What I’ve started doing is tacking the tie in place with Testors’ standard plastic cement (the blue tube). That holds the part sufficiently well so I can return with the liquid plastic cement and brush and create the bond without dislocating the tie in the process. My single-tie test worked; the tie’s properly aligned and mixing the glues hasn’t caused me to blow up our house.
Rick Krall
Tube cement works great in some applications, I use it to apply plastic gutters to plastic buildings as it tends to eat right though any paint in the way.
I use two different glues for building styrene model Tenax 7R and Plastruct, now keep in mind there are several different types of Plastruct cement. It’s just my unprofessional opinion that there is no one glue for all jobs. When building the corners of structures I always clamp them i place first and then use Tenax on a micro brush on the inside seam an it wicks into the seam very nicely. If I am putting tow pieces together that need not be clamped then I will coat the surface of both pieces with Plastruct and then fit them together.I can’t recall how long of a bonding time there is but it’s not very long.
I recently tried a trick I picked up from a guy at the club who is a fantastic modeler in my o/p, when using Plexiglas for modeling he uses straight lacquer thinner on a brush. He says it actually welds of fuses the tow pieces together. If I were to guess I would suspect most glues work the same way and are probably all lacquer based.
If your holding pieces parts etc. in your hand until the glue sets up you may what to go to a site like Micormark and check out some of the really nice clamps they have made specifically for model building.
I’ve also found the mini bar clamps by Kobalt sold in Lowes to be very useful
Your lacquer thinner tip makes sense and, now that I think about it, dupes one from a poster on the Fine Scale Modeler link I posted above. Another reason to shop at the local hardware store!
I have a corner clamp, and I agree they’re great. I intend to use it when I build other portions of the TT, but the pit rail ties are so small I must either tack them or hold them by hand. Trust me–50 ties into the mission, tacking is the way to go!
Rick Krall
I bought a gallon can of MEK twenty years ago and I use it most of the time. Fast drying. I use a fan to keep the air moving. I keep an ounce in a small bottle and use a tiny paint brush to apply.
Rich
I’m always cautious when using solvents indoors. I have 3 windows in my basement, and I have a box fan in front of two of them; one sucking fresh air from outdoors, and the other blowing air out. And, since my workbench is almost directly under the one that blows out, It works!
I posted an earlier response about using Weld-On #3 and didn’t mention anything about odors. I don’t think there is much of an objectionable odor to it and I don’t leave the cap off very long (all solvent cements evaporate rather quickly!). I use a small paint brush to flow it into the seams as it ‘wicks’ just like any water consistency solvent does. I had forgotten about MEK as was mentioned in another post above, but when I worked in a professional model shop in New York many years ago, we used MEK and a Rohm and Hass (mfg of PlexiGlas) solvent cement called Rez’n Bond. ALL plastic adhesives are somewhat dangerous as far as fumes go, but in the small quantities we are using I don’t find them to be that much of a danger. MEK may be the worst, but I wouldn’ t think even that is a problem in small containers.
Someone mentioned using Laquer thinner for a solvent cement for acrylic but I don’t think that would work. I have used laquer thinner to clean Plexiglas of paint or other surface contaminants, but it will craze it if left on too long. It might work on styrene though.
Just thought i would expand on my original posting.
Bob
I’m building a CMR turntable, hence my original question. I’m inserting the pit rail ties, all 198 of them. There’s a bit of play in the slot, and CMR recommends pushing the tie towards the front of the slot to assure perfect alignment. That’s why the 30-second hang time can be problematic–if I don’t remain perfectly still, the tie can slip out of alignment as it bonds.
Rick I built the CMR turntable kit a few years back for a friend, a great kit I liked it so much I didn’t wan to give it to him when it was finished but I did so I had to by one for myself still the box in the work shop.
In this case in my o/p the obvious choice is Plastruct Bondene it’s designed for bonding like materials such as acrylics. I used it when building the CMR kit and was very pleased with the way it worked. I know those ties can be a bit of a chore but all I did was hold the tie in place with a spring loaded pair of tweezers and hit the sides with a micro brush that was dipped in the Plastruct product.
They do make Plastic weld which is great stuff but it’s generally used for bonding dissimilar materials. When using any glue if you really want to speed up the adhesion process you can use this stuff called "Kicker"It’s generally used for speeding up the process when using C/A. The stuff works great only downside is you only get one shot at putting the part where you want it, cause once it touches the other mating surface thats where it’s going to stay
http://www.micromark.com/ZIP-KICKER-SUPER-GLUE-ACCELERATOR-8-OZ-LIQUID,7577.html
Good points. I’ve used Kicker or its equivalent before with CA and styrene–but I’m so obsessed with aligning the ties precisely I leery of anything that bonds that instantly.
BTW, when I bought my bottle of accelerator, the LHS advised that it will burn skin badly if I were to get overspray on my hand. I never tested that theory, but I pass it on in case it may be of value to others.
As to the pit rail ties, I’ve been successful with placing the pit floor on a turned-over pit plate and tacking the ties in place with a small amount of model airplane cement, just enough to secure the tie. I then return with the plastic cement an hour or so later and make the final bond. This prevents the tie from moving when I apply the brush and gives me one last chance to adjust a mis-positioned tie.
Rick Krall