Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => Glue etc. => Topic started by: tizdaz on January 21, 2019, 07:02:28 PM

Title: Bonding perspex?
Post by: tizdaz on January 21, 2019, 07:02:28 PM
Hi guys, im wanting to make a small box (12cm x 8cm) out of clear perspex 3mm thickness, it will be half filled with water, what glue do i use? Ive looked online and ive found some specialist glues but these are for making fishtanks and very expensive, i also read mixed comments that using superglue is fine on small projects which mine is but ive also read that i should not use super glue so would gorilla superglue (im thinking of the gel type) do the job? Or should i also put some silicone over the superglue from the inside when glue is set?


Cheers!
Title: Re: Bonding perspex?
Post by: rsm on January 21, 2019, 07:08:46 PM
Plastic weld works fine (solvent).


http://modelshop.co.uk/Shop/Adhesives/Item/Plastic-Weld-Solvent-57ml/ITM5060 (http://modelshop.co.uk/Shop/Adhesives/Item/Plastic-Weld-Solvent-57ml/ITM5060)
Title: Re: Bonding perspex?
Post by: tizdaz on January 21, 2019, 07:16:33 PM
Something like this?


https://www.amazon.co.uk/Plastic-Weld-Cement/dp/B0053WXLVU (https://www.amazon.co.uk/Plastic-Weld-Cement/dp/B0053WXLVU)


Thanks
Title: Re: Bonding perspex?
Post by: rsm on January 21, 2019, 07:28:34 PM
Yes thatís it. Assemble the joint and then add the solvent with a brush, it gets drawn in by capillary action and stick almost instantly.
Title: Re: Bonding perspex?
Post by: Baldrick on January 21, 2019, 07:29:04 PM
Something like this?


https://www.amazon.co.uk/Plastic-Weld-Cement/dp/B0053WXLVU (https://www.amazon.co.uk/Plastic-Weld-Cement/dp/B0053WXLVU)


Thanks


  But beware, this not a glue like substance, it works by taking the solvent into the joint by capillary attraction and dissolving the joint faces to weld them together homogeneously. Therefore the mating surfaces of your box need to be very precise with close tolerances ( a few thou), the cement will not bridge a gap. Also use a hog hair bristle brush, any normal brush with nylon or plastic bristles will weld together to a blob.
Title: Re: Bonding perspex?
Post by: tizdaz on January 21, 2019, 07:40:14 PM
Ok thanks for that 🙂
Title: Re: Bonding perspex?
Post by: TailUK on January 21, 2019, 08:05:52 PM

  But beware, this not a glue like substance, it works by taking the solvent into the joint by capillary attraction and dissolving the joint faces to weld them together homogeneously. Therefore the mating surfaces of your box need to be very precise with close tolerances ( a few thou), the cement will not bridge a gap. Also use a hog hair bristle brush, any normal brush with nylon or plastic bristles will weld together to a blob.

For gap filling solvent cement you might try Tensol 12 which is basically Plastic Weld with acrylic dissolved in it.  This will give a water tight join but you need to be careful you don't get stress fractures in the edges of the acrylic.
Title: Re: Bonding perspex?
Post by: derekwarner on January 21, 2019, 08:45:41 PM
Miniature stainless bolts and nuts will assist & establish a stress free construction  O0
Title: Re: Bonding perspex?
Post by: tizdaz on January 21, 2019, 09:12:09 PM
Miniature stainless bolts and nuts will assist & establish a stress free construction  O0


But this would mean more work as it would make holes that i would need to fill to keep watertight so think im going to get some plastic weld and use that 🙂
Title: Re: Bonding perspex?
Post by: derekwarner on January 21, 2019, 09:27:08 PM
Daz....


Wilfred Bramble could glue a waterproof perspex tank  O0 .......but give it to Alf & he would  <*< ...yes..drop it on the ground & crack one of those lightly glued highly stressed joints


Derek
Title: Re: Bonding perspex?
Post by: Howard on January 21, 2019, 09:52:42 PM
Tizdaz.
  One trick I have heard about with perspex is id you run and cut edge which will be dull and cloudy is to run it over a open flame and it makes them clear again I think you can look this up on you-tube.
            Regards Howard.
Title: Re: Bonding perspex?
Post by: The Wizard on January 22, 2019, 02:56:08 AM
for an adhesive with some gap filling properties, dissolve perspex filings in acetone. it will take overnight to properly dissolve,give it a shake/stir occasionally.
apply with a brush.


The Wizard
Title: Re: Bonding perspex?
Post by: nmbrook on January 23, 2019, 07:54:57 AM

Tizdaz


UHU special plast working brilliant for me on the waterproof Perspex hatch assemblies on my Seabex build.A little thicker than normal solvent,100% waterproof and you keep optical carity provided you polish the edges up before gluing :-))


Regards


Nigel
Title: Re: Bonding perspex?
Post by: JimG on January 23, 2019, 01:54:58 PM
I have seen reports of a possible problem on a laser cutting forum. Perspex sheet comes in two forms, cast or extruded. It seems that cut edges on extruded sheet can craze with some solvents or cleaners.

Jim
Title: Re: Bonding perspex?
Post by: TailUK on January 23, 2019, 03:06:37 PM
I have seen reports of a possible problem on a laser cutting forum. Perspex sheet comes in two forms, cast or extruded. It seems that cut edges on extruded sheet can craze with some solvents or cleaners.

Jim

Cast acrylic will craze as well as extruded.  The solvent releases the internal stress in the plastic and small fractures occur at right angles to the edge.  The cure is to anneal the plastic by baking it at 82 degrees (C)  or 180 degrees (F) for one hour per millimetre of thickness and cooling for 2 hours this will prevent stress fracture when gluing.