Best Way To Apply Solvent Type Plastic Cement

[pmpexpress]

Just purchased some bottles of Tenax 7R liquid plastic cement for the first time and now find myself needing some suggestions on its application.

In the past, I have always used Plastruct Plastic Weld cement (which comes with a large self contained brush that can produce mediocre results) to glue injection molded plastic kits and Evergreen and Plastruct components together.

Unlike the white Evergreen styrene, the harder, dark gray Plastruct sheets and structural components seem to bond together rather poorly.

With the Tenax cement, it appears that one must utilize one of the following tools to apply it:

A small paint brush

A solvent compatible syringe (i.e., glass or stainless steel), which I have yet to come across

or

A Micro-Mark Touch-N-Flow Applicator



Wondering what application methods other modelers have successfully used to apply solvent based plastic cement.

[Mark W]

Ever since I found out that the 'active ingredient' of Plastic Cement, Plastic Weld, (Probably 7R too), is just MEK, I simply re-fill my old brush cap bottles from a half gallon can of MEK.  That can, which cost the same as a single bottle of plastic cement, will probably be the only one I'll ever need.   

I've never had the need to try any other application tool or technique. 

[pdx1955]

I put a drop of cement in a old plastic lid and use a toothpick to transfer it. Cheap, controlled, and easy.

[peteski]

Ever since I found out that the 'active ingredient' of Plastic Cement, Plastic Weld, (Probably 7R too), is just MEK, I simply re-fill my old brush cap bottles from a half gallon can of MEK.  That can, which cost the same as a single bottle of plastic cement, will probably be the only one I'll ever need.   

I've never had the need to try any other application tool or technique.

Testors Plastic Cement uses MEK.  The 7R uses Methylene Chloride.  While both chemicals dissolve polystyrene, ABS, etc, MEK has a much slower evaporation rate.  That makes a big difference in their application (at least for me).  When I need super fast action I use Methylene Chloride based cement, for ones I need some more time, I use MEK.

[DKS]

I use MEK almost exclusively, and apply it with a small (#0 or thereabouts) inexpensive brush. I find the speed just right. Perhaps it's because I've become used to it, and know what to expect. I get MEK by the gallon from Home Depot, and pour it into a small glass bottle with a polyseal lid. I also have some methylene chloride on hand, but I only use that when bonding Plastruct (which I almost never use) or Plexiglas. Commercial plastic bonding products like Tennax are a means to part with too much money.

 

[MK]

DKS, is it on Home Depot's webstie?  Do you have a link?  I tried MEK and Methyl Ethyl (Ketone) and got nothing.  Perhaps it's under a trade name?

[DKS]

DKS, is it on Home Depot's webstie?  Do you have a link?  I tried MEK and Methyl Ethyl (Ketone) and got nothing.  Perhaps it's under a trade name?

I bought it quite a long time ago (like a few years back). MEK was briefly taken off the market, then it reappeared.

Here it is at Lowe's:

https://www.lowes.com/pd/Jasco-128-fl-oz-Fast-to-Dissolve-Methyl-Ethyl-Ketone-MEK/50298051

 

[Maletrain]

Where can I get methylene chloride these days?

[DKS]

Where can I get methylene chloride these days?

I had to get mine from an online chemical supply company. Bought it maybe 6-7 years ago, so I have no clue who, but just do a search and you should find someone who will sell a small amount. I just got a pint, and I've barely put a dent in it.

[robert3985]

Like DKS, I use a small, inexpensive watercolor brush to apply my Tenax.  If I need more of it, then I use a slightly larger brush.  After a bit, the glue brushes become stiff with the Styrene they've picked up during glue applications, but just swish them around in the Tenax and the Styrene in them dissolves quickly.

As a side-note, I use a larger, stiffer brush and Tenax to attach brass or stainless etched running boards to plastic cars. Although the running boards can still be peeled off accidently, they can be easily re-glued to the plastic standoffs on the roofs of most cars that have plastic running boards to begin with.

I assume that the Tenax dissolves the plastic standoffs enough so the etched metal running boards sit down in the melted plastic, and the Tenax soaked paintbrush picks up a bit of the plastic and it dries on the tops of the metal running boards...a VERY thin layer that I cannot see with my Optivisors.

I don't man-handle my cars, so this method works great for me and for the cars I've assembled on commission or for trade. 

Photo (1) - GoldenWest U.P. CA-3/CA-4 kit with Plano etched running boards glued on with Tenax.  Photo is from another post dealing with the kitbash and superdetaling of this model:


Cheerio!
Bob Gilmore

[pedro]

I can vouch for the Tenax/Touch n Flow applicator combo. With practice, nothing else comes close for precise application of cement. You just stick the glass end into the bottle and capillary action draws the Tenax up into it. I have several of the applicators on hand since they’re almost impossible to refill until 100% of the Tenax is evaporated out of the needle. Obviously, the applicator will also work with MEK or similar solvents.

[DKS]

As a side-note, I use a larger, stiffer brush and Tenax to attach brass or stainless etched running boards to plastic cars. Although the running boards can still be peeled off accidently, they can be easily re-glued to the plastic standoffs on the roofs of most cars that have plastic running boards to begin with.

I used to do that. Anymore, I use brush-on Krazy Glue, which allows you to apply a really nice thin, well-controlled layer of CA. I've found it to be a bit more reliable than the dissolved-plastic-pseudo-bond technique.

[pedro]

I used to do that. Anymore, I use brush-on Krazy Glue, which allows you to apply a really nice thin, well-controlled layer of CA. I've found it to be a bit more reliable than the dissolved-plastic-pseudo-bond technique.

Something else to consider for roofwalks: crystal-clear silicone aquarium sealant. Apply a thin layer with a micro bush and the etched roofwalks aren't going anywhere. It also allows them to expand and contract without getting wavy. This was recommended by Intermountain when they first started making kits.

[pmpexpress]

Thanks for all of your tips and suggestions.

Was actually looking for a quicker setting solvent based plastic cement.

According to Pete's reply, Tenax should serve my needs.

Based upon DKS's, Bob's, and Pedro's replies, I will go ahead and try both the #0 brush and the Touch N Flow applicator.

My guess is that different situations will call for the use of either of the suggested solvents and aforementioned application tools.

Another topic that I had not yet considered was a suitable way to adhere brass and/or stainless steel detail parts to plastic.

Can always count on The Railwire for great ideas and methodologies.

[Bill H]

Been using Tenax for years with the touch n' flow needle applicator. Clearly my preference for most situations. Guess I got hooked building several hundred IM kits over the years- back when they were a steal on the 'Bay.

Kind regards,
Bill