Tamiya and testors cement issues

[jamesG]

While trying to rebuild nightstalker vette I have encountered problems with both not doing a very good job of bonding parts together. On original kit parts tamiya was hit and miss. It bonded the hood and scoop ( both white plastic) and blower parts ( both black plastic) but black to white plastic doesnt seem to work well.

Neither tamiya or testors seem to provide a strong bond between kit and evergreen styrene. 

Anyone have these issues or any ideas what the issue could be?

[1972coronet]

You need cyanoacrylate ( "CA" ) glue and / or Plastruct Bondene ( "cold weld" ) cement .

[stitchdup]

I find the same with black styrene, it always seems to be that bit harder than the other colours. I have had some success by putting a small amount of poly cement on both faces you are glueing, and let it sit a few minutes before putting together. Generally if its black plastic i go for generic superglue from the pound/dollar shop

[gman]

I have used Testor's liquid cement for plastic to plastic bonding, but find Tenax 7R to be much more predictable and quicker to bond/dry completely. It is also a fairly "hot" solvent that will usually work on most types of styrene.

For every type of application and material, there is an adhesive best suited to the task. Liquid cements, super glues, epoxies, glues designed for clear parts- all have their places for attaching certain types of parts on a model. The trick is to know where and when to use them. 

For dissimilar plastics that won't bond together using a traditional liquid cement, super glue is a natural, especially if the parts are not clear, and the joint will be finished/puttied/sanded prior to painting.

[jamesG]

27 minutes ago, 1972coronet said:

You need cyanoacrylate ( "CA" ) glue and / or Plastruct Bondene ( "cold weld" ) cement .

How does bondene compare with tamiya and testors? It seem to work in the same way, is it just a "hotter" formula?

[jamesG]

23 minutes ago, stitchdup said:

I find the same with black styrene, it always seems to be that bit harder than the other colours. I have had some success by putting a small amount of poly cement on both faces you are glueing, and let it sit a few minutes before putting together. Generally if its black plastic i go for generic superglue from the pound/dollar shop

Testors directions say to apply to both surfaces wait 20 seconds, join parts and hold 20 seconds. It didn't work maybe a longer wait time?

[jamesG]

7 minutes ago, gman said:

I have used Testor's liquid cement for plastic to plastic bonding, but find Tenax 7R to be much more predictable and quicker to bond/dry completely. It is also a fairly "hot" solvent that will usually work on most types of styrene.

For every type of application and material, there is an adhesive best suited to the task. Liquid cements, super glues, epoxies, glues designed for clear parts- all have their places for attaching certain types of parts on a model. The trick is to know where and when to use them. 

For dissimilar plastics that won't bond together using a traditional liquid cement, super glue is a natural, especially if the parts are not clear, and the joint will be finished/puttied/sanded prior to painting.

I have used tenax in the past I found that Flex-I-File plast-I-weld worked better. Your thoughts?

Yeah, I understand different glue applications and dissimilar materials require different products. However kit parts wit obvious exceptions should be the same material, no?

Both products I've used so far have been liquid cement not tube glue.

[gman]

I haven't tried Flex-I-File plast-I-weld, mostly because Tenax 7R has met my needs and has worked well. 

One thing I have found (as a dedicated kit basher for decades) is that there is a wide variety in the composition of model kit styrene from different manufacturers, and even from the same manufacturers over different time periods- things like plasticizers, colorants and who knows what else can affect how a solvent will affect one piece vs. another you are trying to glue together. What bonds one type may melt another and turn it into a gooey mess (I am talking to YOU, AMT circa 1989). Revell plastics from the same period varied too- some were brittle and didn't always readily bond well with liquid cement. Trying to tack together different grades of styrene works best with light applications of a hot solvent, one that is hot enough to melt both types, and yet evaporate quickly so as not to soften the plastic too much.

Todays new kit plastic is less predictable still- more reactive to paints and glues than North American-sourced plastics, so a hot, fast-drying solvent in your glue, and a cooler solvent (or good barrier coat) in your paint is more important than ever.

[jamesG]

10 minutes ago, gman said:

I haven't tried Flex-I-File plast-I-weld, mostly because Tenax 7R has met my needs and has worked well. 

One thing I have found (as a dedicated kit basher for decades) is that there is a wide variety in the composition of model kit styrene from different manufacturers, and even from the same manufacturers over different time periods- things like plasticizers, colorants and who knows what else can affect how a solvent will affect one piece vs. another you are trying to glue together. What bonds one type may melt another and turn it into a gooey mess (I am talking to YOU, AMT circa 1989). Revell plastics from the same period varied too- some were brittle and didn't always readily bond well with liquid cement. Trying to tack together different grades of styrene works best with light applications of a hot solvent, one that is hot enough to melt both types, and yet evaporate quickly so as not to soften the plastic too much.

Todays new kit plastic is less predictable still- more reactive to paints and glues than North American-sourced plastics, so a hot, fast-drying solvent in your glue, and a cooler solvent (or good barrier coat) in your paint is more important than ever.

Got ya. I would think there wouldn't be much of a variation within a single kit though. Looks like I'll be making a glue run. Plast-i-weld, ca, epoxy, I'll find something eventually I guess.

Thanks for all the info 

[gman]

16 minutes ago, jamesG said:

Got ya. I would think there wouldn't be much of a variation within a single kit though. Looks like I'll be making a glue run. Plast-i-weld, ca, epoxy, I'll find something eventually I guess.

Thanks for all the info 

I suppose that depends. Many years ago (now vintage kits), it wasn't unheard of to have chrome trees made up of different plastics than the majority of the sprues.

Most glues used in our hobby will work either through a chemical bond (think standard model glues- liquid, tube), or a mechanical bond (think epoxy, white glue, Micro Crystal Clear, super glue, even clear enamel).

Epoxy and other mechanical bonds are good for where you want to glue plated, painted or clear parts in a manner that won't affect that paint, plating or optical clarity. Chemical bonds are great where the glued seams will be sanded, puttied, primered and painted over top of the joint. Shop with that in mind, so you have a few different methods available so as not to screw up your hard work.

[1972coronet]

Thank you for the much better answers and explanation , @gman . 

I , too , recommend that anyone have more than one type of adhesive on hand  ( I prefer Tamiya "orange cap" cement , Tamiya "green cap" bonding cement , el-cheapo dollar store "super glue" [ the stuff in the red bottle with a black cap is the best ! ] , the aforementioned Bondene , and finally , Mod Podge gloss-clear ) .

Best of luck !

[jamesG]

2 hours ago, gman said:

I suppose that depends. Many years ago (now vintage kits), it wasn't unheard of to have chrome trees made up of different plastics than the majority of the sprues.

Most glues used in our hobby will work either through a chemical bond (think standard model glues- liquid, tube), or a mechanical bond (think epoxy, white glue, Micro Crystal Clear, super glue, even clear enamel).

Epoxy and other mechanical bonds are good for where you want to glue plated, painted or clear parts in a manner that won't affect that paint, plating or optical clarity. Chemical bonds are great where the glued seams will be sanded, puttied, primered and painted over top of the joint. Shop with that in mind, so you have a few different methods available so as not to screw up your hard work.

Thanks again for all the info.

I've been out of the hobby for a while and most of my "glues" have either evaporated or turned to useless blocks so I'll just have to grab a good variety. 

[Straightliner59]

You can pick up a can of Weld-On 4 at Home  Depot.  It's very similar to Tenax or the Flex-i-File stuff. Lots cheaper, too!

[slusher]

Black plastic is hard to glue. Works better if you knock the shine off with sandpaper...

[SfanGoch]

16 hours ago, Straightliner59 said:

You can pick up a can of Weld-On 4 at Home  Depot.  It's very similar to Tenax or the Flex-i-File stuff. Lots cheaper, too!

Bingo! However, not similar, it's the same. $14-16 for a pint, depending from where you buy it. I use the Sci-Grip version from IPS. Every modeling-specific brand people mention (Tenax, Ambroid, etc.) is nothing more than generic methylene chloride packaged in 1 oz. bottles and sold at a premium.

[jamesG]

18 hours ago, SfanGoch said:

Bingo! However, not similar, it's the same. $14-16 for a pint, depending from where you buy it. I use the Sci-Grip version from IPS. Every modeling-specific brand people mention (Tenax, Ambroid, etc.) is nothing more than generic methylene chloride packaged in 1 oz. bottles and sold at a premium.

I'm no chemist but it doesn't seem that "every" brand is methylene chloride. Tamiya is acetone, testors is I believe methyl ethyl ketone etc. While similar they are not the same thing.

[SfanGoch]

I was specifically referring to Tenax, Ambroid, Bondene and other like brands.

[jamesG]

9 hours ago, SfanGoch said:

I was specifically referring to Tenax, Ambroid, Bondene and other like brands.

Ah. I got ya.

[dartman]

I use mek on about all my stuff and have never found anything it would not work on.....

 

[Deuces ll]

On 7/30/2020 at 1:11 PM, jamesG said:

While trying to rebuild nightstalker vette I have encountered problems with both not doing a very good job of bonding parts together. On original kit parts tamiya was hit and miss. It bonded the hood and scoop ( both white plastic) and blower parts ( both black plastic) but black to white plastic doesnt seem to work well.

Neither tamiya or testors seem to provide a strong bond between kit and evergreen styrene. 

Anyone have these issues or any ideas what the issue could be?

That's why I like white styrene only kits.... When it comes to glueing any other color plastic, ya gotta switch over to something stronger....