Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[GG]

An elderly model was recently taken out of storage and refitted with RC and battery with a view to having some nostalgic sailing.  Before it could placed in the water some small details that had either become loose or even fallen off required refitting.


They had been fixed to the model using a contact adhesive which, over the years, had become brittle and lost most of its strength.  Now, I'll confess that we are talking about a couple decades between the models original build and the discovery of the glues failure.  So, I guess a fair response could be "what do you expect after all this time?" and maybe it is unusual to some for a model to be kept this long?


However, my oldest model is heading for 5 decades and all its details are still firmly attached.  The difference being that they were secured with "double sided" adhesive tape which seems to just as firm as the day it was first used.


It might be interesting to hear from others about the long term durability of the adhesives we use in this hobby.  Fortunately all the glues used for structural joint still seem to be secure and reliable!


Glynn Guest

[TailUK]

It's interesting point.  New glues (which are probably just variations of existing glues) turn up at times and people ask "Will it last 25 years?" If it was only invented last year, who knows?.  I'm afraid I tend to stick (no pun intended) with stuff I'm familiar with and sometime use a mechanical fixing too.

[roycv]

Hi I have found double sided tape on Milar sails a long time fix, in fact I have been trying to work out how to unfix the DS tape joint for a small adjustment.
Anyone got any ideas?
Roy

[KitS]

Hi I have found double sided tape on Milar sails a long time fix, in fact I have been trying to work out how to unfix the DS tape joint for a small adjustment.
Anyone got any ideas?

Have you tried a hair dryer over the DS tape?

I did that one (and I can't remember just why I tried the hair dryer) and it worked fine, but it needed new DS tape afterward as the old stuff just wouldn't stick any more.

[roycv]

Hi Kits, thanks for the idea I will try it out.
all the best
Roy

[Colin Bishop]

I think it is a bit like 'how long is a piece of string'. It all depends on the type of glue, the quality of that type, the surfaces being glued, the environment in which the bond was made and the conditions under which the glued joints have been kept (hot/dry/wet/damp etc). Superglue joints are known to go brittle in time and styrene can eventually break down due to its chemical makeup.

Wood and boiled horses are known to have lasted well though... 

Colin

[chas]

My oldest surviving model, a Spanish fishing boat is 53 years old and still solid. Cascamite was used for the ply joints and good old balsa cement for all the balsa, and balsa to ply planking.
     Among more recent models, less than 25 years old I've had Araldite fail and styrene joins have failed on models even younger.
    None of my models have been especially well stored, garages, lofts etc.
   Interestingly, my favourite model, double mahogany planked has always been in the house, central heating etc and is still as good as when I finished it, that was with PVA white glue.
  I guess there is a lot of luck involved
   Chas

[Tug Fanatic]

I wonder how much of the life of glue is as much to do with preparation and selection of the right type of glue as much as it is to do with the glue itself. This would tend to reduce the element of chance and replace it with the skill of the constructor in choosing & properly using the correct glue.

Aircraft builders & restorers are very concerned about glue & I have found their guidance useful:
http://eaavintage.org/tech-tip-wood-glues/
or
http://simplexaero.com/ultralight_construction/glue_for_aircraft_construction/

I do wonder about both the structural integrity of the wood and the glue used in the manufacture of some plywood.

[GG]

Useful comments, thanks!
TailUK - We clearly think alike on this topic, "I know it works so that's what I'll use".


Tug Fanatic - Two useful sites you refer to. Luckily I seem to be doing structural glued joints in my models correctly, just need to do the same with the stuck on details...!


Glynn Guest 

[Tug Fanatic]

I am sure that "double sided adhesive tape" covers products from the cheap & cheerful but useless to the unbelievably expensive but wonderful for specific jobs.

How do you tell a "good" and long lasting double sided tape for model boat use from a "poor" short life one?

Deluxe Materials have a series of pdf's that look at joining most materials.
https://deluxematerials.co.uk/collections/glue-charts

[roycv]

Hi All, most of my models are PVA glue and wood.  There is a big difference with a PVA joint with a peg type clamp.  When all set and dry when pulling the joint apart it will give, and then pop open showing crystals of glue on the wood surface.

 If you screw clamp the joint it will tare itself apart before the joint fails.  A really big difference.
regards

Roy