Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: Paul on May 26, 2012, 02:35:16 pm

Title: Polystyrene sheet and plywood; help ?
Post by: Paul on May 26, 2012, 02:35:16 pm
Polystyrene sheet and plywood; help ?

HI folks,

I hope someone can help – it is my time using polystyrene and plywood for model boat building and I am having problems.
Humbral poly cement is great for poly to poly.

However, I have tried two different for poly to plywood. UHU plus acrylit and Pacer Z-poxy appeared to work but after three days poly peeled away from the plywood. This is causing me a lot of re-working and not found an adhesive that works.

Can any one recommend an adhesive that will stick poly to plywood please ?

Paul.
Title: Re: Polystyrene sheet and plywood; help ?
Post by: regiment on May 26, 2012, 04:33:46 pm
good old evostick
Title: Re: Polystyrene sheet and plywood; help ?
Post by: Circlip on May 26, 2012, 04:57:30 pm
Scrub surface of Poly with an abrasive to "flatten" the surface gloss and wash with a detergent before Evosticking it.

  Regards  Ian.

  Glue advise to peruse

    http://www.thistothat.com/

  
Title: Re: Polystyrene sheet and plywood; help ?
Post by: funtimefrankie on May 27, 2012, 08:12:09 am
Thick super glue from 5 Star adhesives... works for me
Title: Re: Polystyrene sheet and plywood; help ?
Post by: Bryan Young on May 28, 2012, 06:13:39 pm
Good double-sided tape does the job every time. Quick'n'easy and permanent (at least 20 years as my models have proved). BY.
Title: Re: Polystyrene sheet and plywood; help ?
Post by: essex2visuvesi on May 29, 2012, 05:47:00 am
NO nails is quite effective as well
Title: Re: Polystyrene sheet and plywood; help ?
Post by: portside II on May 30, 2012, 08:37:00 pm
i just go for the hot glue gun it works for me as none of my boats have fallen apart yet  :o ,
Mind they are also covered with news paper and PVA then glassed over  O0 .
daz
Title: Re: Polystyrene sheet and plywood; help ?
Post by: DickyD on May 30, 2012, 11:01:54 pm
ADHESIVES
Adhesives may be in tube form (polystyrene cement) or in liquid form such as Humbrol Liquid Poly or MEK
(methyl ethyl ketone) which is best applied with a brush. The technique is to apply a few drops of the solvent
and the glue will run down the joint by capillary attraction. The following glues are recommended:
Fibreglass to plastic:   two-part epoxy (Devcon, Araldite, Speed Epoxy) - 10 min. or 1 hour. 
Plastic to plastic:   ordinary plastic solvent (Revel, Liquid Poly, Slaters, MEK). 
Whitemetal to whitemetal: two-part epoxy (5min.) or thick superglue (Pro-Bond, MFA etc.)   
Whitemetal to plastic:   two-part epoxy or thick superglue. 
Wood to plastic:   two-part epoxy, thick superglue or contact adhesive. 
Brass to plastic:   R/C Modellers craft glue or thick superglue. 
Rubber Fendering:   contact adhesive (UHU, Bostik). 
Window glazing:  Weldbond, RC Modeller's Craft Glue or clear contact adhesive (UHU, Bostik

http://www.modelslipway.com/Hints%20n%20tips.pdf
etc.) 
Title: Re: Polystyrene sheet and plywood; help ?
Post by: Paul on June 01, 2012, 05:06:41 pm

Thanks for advice above.

Have tried different adhesives but still no luck

If I was starting again I would go for all wood Hull and just use poly sheet for removable substructures thereby avoiding any poly to wood glueing

Wood to plastic:   two-part epoxy, thick superglue or contact adhesive - tried these and the poly sheet does not work - many glues do have a warning that do not work with polystyrene - and they don't, some say any plastic but these do not either !!!

Trialling No Nails and Liquid nails - will report back



Title: Re: Polystyrene sheet and plywood; help ?
Post by: Colin Bishop on June 01, 2012, 05:27:01 pm
Bryan's earlier suggestion of doublesided tape is the best one, sticks to anything. They use it to hold aeroplanes together so it should be adequate for a model boat. Basically what you have is a thin film of very strong adhesive between two paper backings. Peel off one and stick to one surface then peel off the other and bring the two surfaces together - but get it right first time, once it sticks it sticks!

Obviously you need to get the right type but there's plenty of information if you Google double sided tape.

Colin
Title: Re: Polystyrene sheet and plywood; help ?
Post by: Islander51 on June 02, 2012, 09:09:23 am
Another choice is Uhu solvent free all purpose cement, this comes in a tube with a green top,
and it doesn't attack expanded polystyrene, I know this because I'm looking at some drying on a
piece of ex-poly as I speak.   :-))

Edward.
Title: Re: Polystyrene sheet and plywood; help ?
Post by: scoop on June 02, 2012, 09:54:38 am
I remember building my first Fiesta yacht, we (the Fiesta fraternity) used photo mount spray to stick the plastic deck to the ply substructure, it's still there after all these years.
Scoop
Title: Re: Polystyrene sheet and plywood; help ?
Post by: Circlip on June 02, 2012, 10:00:48 am
Glad you've informed me that contact adhesive (non-solvent type) doesn't work, All the UPVC door panel manufacturers I've come into contact (Bad pun) with will be highly interested than they've been getting it wrong.   :-))

   Regards  Ian.
Title: Re: Polystyrene sheet and plywood; help ?
Post by: hollowhornbear on June 02, 2012, 10:15:29 am
 I think i should add some more info, here, I know Paul. what he is trying to do is use polystyrene sheet on plywood frames for the hull of a Puffer. he is not bonding a large flat area.
hope this clarifies the situation.
Title: Re: Polystyrene sheet and plywood; help ?
Post by: Colin Bishop on June 02, 2012, 10:18:44 am
Quote
I think i should add some more info, here, I know Paul. what he is trying to do is use polystyrene sheet on plywood frames for the hull of a Puffer. he is not bonding a large flat area.
hope this clarifies the situation.

My immediate reaction to that is that it probably isn't a good idea as it will be very difficult to get a proper bond between the two materials in that situation. Why not just use ply sheet instead and there will be no problem?

Colin
Title: Re: Polystyrene sheet and plywood; help ?
Post by: Paul on June 05, 2012, 01:50:25 pm

Thanks all,
I think I will take Colin's advice All Hull Parts to be Wood.

Surprised that no adhesive has been made that will do the job - having read the data on numerous adhesives it is amazing how many do not include poly and many explicitly state not to use on poly.

Having tried quite a number of adhesives I haver come to the conclusion that I should stick with wood for all parts of the hull,  bulkheads, skins and combing onto which to place the poly sheet substructures.

It is not worth the risk of relying what appears to be a problem with poly sheet and wood.