Model Boat Mayhem

Mess Deck: General Section => Beginners start here...! => Topic started by: Martin (Admin) on July 08, 2019, 11:09:28 pm

Title: More chat about ABS & Glues
Post by: Martin (Admin) on July 08, 2019, 11:09:28 pm
ALWAYS test glues, paints, fillers on scrap before committing to the final job!   O0
Title: Re: More chat about ABS & Glues
Post by: Martin (Admin) on July 08, 2019, 11:09:58 pm
Shouldn't experience any issues with those materials. You need to be careful with modified acrylic on some clear plastics like polycarbonate and PMMA as it can craze them. Epoxy is pretty much inert on anything, but the bond is completely mechanical, so the plastic surfaces need to be well keyed before bonding.
Title: Re: More chat about ABS & Glues
Post by: Martin (Admin) on July 08, 2019, 11:10:11 pm

Agreed but some ABS / 'hard plastic' single part glues have high solvent content and if used too liberally or the ABS is very thin..... !   {:-{
Title: Re: More chat about ABS & Glues
Post by: Martin (Admin) on July 08, 2019, 11:10:30 pm
All the glues I listed are twin component adhesives, Martin. You can't fuse wood to ABS, it has to be bonded.
Title: Re: More chat about ABS & Glues
Post by: Martin (Admin) on July 08, 2019, 11:14:59 pm
 
Hey Andy,

Rather than hijack Phil22  - Billings Banckert 516 build topic... I though I split the glue chat off here....
( https://www.modelboatmayhem.co.uk/forum/index.php/topic,63135.0.html )

This came up on Utube today.... what do you think?


Title: Re: More chat about ABS & Glues
Post by: Subculture on July 09, 2019, 09:38:29 am
I don't use any of those grab adhesives for model work. I'm sure some find them useful, but I tend to work with small quantities of adhesives, so I like to use modified acrylics, epoxies and cyano and occasionally Aliphatic PVA on wooden structures.
Title: Re: More chat about ABS & Glues
Post by: imsinking on July 09, 2019, 10:04:39 am
Has anyone tested the longevity / resilience of the 'hot glues' beloved by youtubers ? one gent even glued in a motor using hot glue (fall apart when the motor heats up ?)
I'm slowly gathering together all the wherewithal to do a Graupner Condor 9 unstarted kit , a lot of what's in the build sheet is not available anymore eg Stabilit Express for one . . . I'm reluctant to proceed until certain of the suitability of the modern glues as once the top ABS deck is glued to the hull you cant get at anything , jet drives / servo's etc , get a leak and i'm scuppered . . .
Bill
Title: Re: More chat about ABS & Glues
Post by: Subculture on July 09, 2019, 10:23:32 am
Stabilit Express is a modified acrylic glue. So although that brand might not be readily available now, you can get alternatives. If you want some bulk to the glue, you can use fillers like glass strands, which will further enhance strength.

Starloc adhesives market a modified acrylic with similar qualities to Stabilit Express called 'Stable xpress'-

https://shop-4-glue.com/stable-xpress-acrylic-glue-for-plastic-metal-wood-modeling-abs-grp-model-boat-adhesive-402-p.asp (https://shop-4-glue.com/stable-xpress-acrylic-glue-for-plastic-metal-wood-modeling-abs-grp-model-boat-adhesive-402-p.asp)
Title: Re: More chat about ABS & Glues
Post by: Tug Fanatic on July 09, 2019, 11:03:38 am
In the same series they did at test of epoxies which suggests that they are not all the same.
https://www.youtube.com/watch?v=XObmZIbHOzY (https://www.youtube.com/watch?v=XObmZIbHOzY)


Longevity is the great unknown with so many glues. Even old friends like Cascamite seem to fail with time.

Hot glue is fine as long as you don't tax it much. Yes heat can be a problem softening the glue but cold is much worse. Those that I have tried get very brittle & loose any desire to hang on to anything. I use it for foam (depron & epp) model aircraft where on a very cold day bits can easily fall off if knocked. I am sure some are better than others but.................
Title: Re: More chat about ABS & Glues
Post by: unbuiltnautilus on July 09, 2019, 09:05:27 pm
I went through a spell using hot glue to hold timber guides in the bottom of a fibreglass hull. These guides held the batteries and radio trays in position. The model took on some water (salt water..might be relevant..) and within a month all the glue joints had let go from the hull. Nice and cleanly I might add!. Now I restrict hot glue use to sticking in speed controls and receivers, or providing shake proof blobs over electrical solder joints.
Title: Re: More chat about ABS & Glues
Post by: Tug Fanatic on July 09, 2019, 09:52:32 pm
So by the time hot glue doesn't like heat, cold nor water I think its usefulness in model boats is rather limited!

There is also low temperature hot melt glue which is even worse regarding the above problems but useful for my foam model aircraft.
Title: Re: More chat about ABS & Glues
Post by: Subculture on July 09, 2019, 10:17:26 pm
Hot glue is handy for certain things. It's quite useful for sticking things to difficult plastics like polypropylene and polyethylene. If materials are absorbent like wood , and the parts are exposed to moisture the glue will let go. it also tends to be rather messy, so not suitable for anything that needs a neat appearance.
Title: Re: More chat about ABS & Glues
Post by: coch y bonddu on July 09, 2019, 10:24:11 pm
Hot glue simply forget it in my opinion....stuck some plastic cones on my slot car track and they can easily be knocked off with a scaletric car...not good in my honest opinion






Dave
Title: Re: More chat about ABS & Glues
Post by: malcolmfrary on July 10, 2019, 09:55:59 am
Hot glue mostly just forms a mechanical join to whatever surface it is applied to.  The heat "might" create a key on some materials (by locally melting the surface), others might need a good coarse abrading.  If the plastic that is being joined has similar thermal characteristics to the "glue" (which is really just a stick of plastic) you might end up with a welded join, with pretty much the same perils as welding metal, but at a lower temperature.
It does tend to be messy, readily forming strings, and tends to look like something that Fraggles would look down on with distain, but every so often it is "the" answer.  But certainly nothing like as often as it was originally touted to be when it first appeared.