Jump to content
Gazzas

What makes a stronger bond between large parts?

Recommended Posts

Hi everyone,

    For a long time I've wondered which bond will prevent the popping of seams while we file, sand, fill, file and sand again. 

 

The only thing I've ever used that I feel hasn't failed me yet is sprue glue.  My sprue glue was made with Tamiya Liquid cement and a variety of sprues.

 

Liquid glue (both Tamiya and Contacta) has failed me at times especially along wing joints as I worked along the wing root.

 

I've used CA for smaller parts, but never really trusted it for parts that might get some flexing action.

 

I've also got a bottle of Micro Weld which I haven't tried in that type of wing or fuselage joint.

 

Why not stick to sprue glue?  Well...   It takes a long time to cure.  And...if you get too much on one spot, you get a nasty sink mark that takes a real (real!) long time to harden.

 

So, I'm looking for something in which to place my trust as I get ready to join the halves of my Albatros fighter which has really flexible plastic.

 

What would you recommend?

 

Thanks,

 

Gaz

Share this post


Link to post
Share on other sites

You see, Gaz, your home-made sprue-glue is essentially nothing more then your home-made version of an over-the-counter regular tube-type model airplane cement.

 

I use a combination of Testors Non-Toxic cement and Loctite Control Gel.

 

Because it is slower-hardening and uses a less aggressive solvent, the Non-Toxic cement is very forgiving of excess, especially on external surfaces where it can be wiped-off within a few seconds without leaving a blemish(!), giving me more time to adjust flexible fuselage and wing-halves.

 

I first bead the Testors between the locater-pins, corners, etc., skipping about 1/4" (6mm) for each.

 

Next I apply a glob of Loctite at the pin/corner locations I skipped with the Testors.

 

Then, I quickly join the parts, wiping off excess with a tissue, carefully aligning and closing the seam(s) and finishing with elastic bands, tape, etc.

 

The Loctite Control Gel compensates for the longer setting time of the Testors by normally setting-up in 10-30 seconds.

 

If I discover a gap that needed more glue, depending on it's size, I might use both glues again, re-applying the Loctite at any gapping corner, a spot in the middle of an open seam, etc.

 

Then I finish working on the assemblies, etc., finishing as I go. 

Edited by Gigant

Share this post


Link to post
Share on other sites

My new favourite liquid cement is Mr. Cement from Gunze (GSI). It's a little slower-drying than Tamiya Extra Thin, but seems to create stronger bonds, especially on larger parts. I still use TETC a great deal, but Mr. Cement gets a lot of use now, too. Apparently it will work on the ABS-style plastic in 21st Century kits, though I haven't tried that myself yet.

 

Kev

Share this post


Link to post
Share on other sites

I use a combination of Testors Non-Toxic cement and Loctite Control Gel.

 

Because it is slower-hardening and uses a less aggressive solvent, the Non-Toxic cement is very forgiving of excess, especially on external surfaces where it can be wiped-off within a few seconds without leaving a blemish(!), giving me more time to adjust flexible fuselage and wing-halves.

 

I first bead the Testors between the locater-pins, corners, etc., skipping about 1/4" (6mm) for each.

 

Next I apply a glob of Loctite at the pin/corner locations I skipped with the Testors.

 

Then, I quickly join the parts, wiping off excess with a tissue, carefully aligning and closing the seam(s) and finishing with elastic bands, tape, etc.

 

The Loctite Control Gel compensates for the longer setting time of the Testors by normally setting-up in 10-30 seconds.

 

If I discover a gap that needed more glue, depending on it's size, I might use both glues again, re-applying the Loctite at any gapping corner, a spot in the middle of an open seam, etc.

 

Then I finish working on the assemblies, etc., finishing as I go. 

The Loctite Control Gel compensates for the longer setting time of the Testors by setting-up in 10 seconds.

 

And this never fails?

Share this post


Link to post
Share on other sites

No-because this method gives me the essential elements-time and strength.

 

All finished models I have shown here were done with this technique!

 

For bi-plane strut attachment points, I use a dab of each.

Edited by Gigant

Share this post


Link to post
Share on other sites

My new favourite liquid cement is Mr. Cement from Gunze (GSI). It's a little slower-drying than Tamiya Extra Thin, but seems to create stronger bonds, especially on larger parts. I still use TETC a great deal, but Mr. Cement gets a lot of use now, too. Apparently it will work on the ABS-style plastic in 21st Century kits, though I haven't tried that myself yet.

 

Kev

 

I've seen a lot of bottles of Mr. Cement at Mr Toys.  They look a bit more dated than the one BNA is selling right now.  I wonder if it's the same stuff.  Are all of those Mr-products from the same place?

 

Gaz

Share this post


Link to post
Share on other sites

Just kidding. I had the same problem with a Revell p-39 last week and I'm going to use epoxy as my next experiment.

 

For just styrene plastic, I have had epoxy joints yellow and shrink.

 

The Testors Non-Toxic Cement's solvent actually softens the plastic and welds the plastic joints.

Share this post


Link to post
Share on other sites

I've seen a lot of bottles of Mr. Cement at Mr Toys.  They look a bit more dated than the one BNA is selling right now.  I wonder if it's the same stuff.  Are all of those Mr-products from the same place?

 

Gaz

 

Gaz, this is the stuff I use:

 

GSMC129.jpg

 

Available from BNA at the following link:

 

https://www.bnamodelworld.com/hobby-tools-supplies-cement-glue-gsi-creos-gsi-mc129

 

Kev

Share this post


Link to post
Share on other sites

I use faller super expert glue followed up by a light pass of testors liquid glue and have, so far, never had a problem with joint separation.

Share this post


Link to post
Share on other sites

Oh yeah, I just discovered the long curing time and softening issues of the sprue-glue with my recent F-23 build. Truly annoying indeed, but it's good for adding volumes and change the shapes. I found out the perfect concoction, let's say the numbers are quantities - (5) very thin shavings of plastic; (3.5) revell's contacta Ca glue; and (0.5) dust from a sanded dry piece of filler. The Tamiya plastic is the softest one and thus has the longest curing time. The Zoukei-mura plastic is the perfect one - it melts flawlessly in the glue and dries in 1 day even in a relatively thick layer. The Hobbyboss plastic cannot melt properly in the glue and there are still harder particles left in the paste. The Academy plastic is very very similar to the Tamyas plastic. So these are my observations so far.
Another method that I use is to glue just another layer of plastic on the inner side of the surfaces, which basically doubles the margin for sanding. Check out the upper fuselage on the inner side :)

 

photo_1.jpg

 

and of course sometimes the overlapping (alignement) pieces are indispensable for the largest parts as well:

 

photo_2.jpg

Edited by F`s are my favs

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×