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[Gaffers]

As I continue to be amazed by Debs knowledge of .....well just about everything I was pondering this question while building my sailing dinghy:

Why does epoxy resin, which sticks solidly to pretty much everything, not stick to plastics?

Its great because as I layer up the epoxy on the wood it sticks to my boat and not my tools , but before I write into Brainiac........  

[JamesV6CDX]

I may know the answer, but seeing as you want Debs... you'll have to wait 'till she arrives

[Gaffers]

smarty pants!!  

Why not try and beat her then..... I have no idea of the answer so baffle away mate  

[Debs.]

As I continue to be amazed by Debs knowledge of .....well just about everything I was pondering this question while building my sailing dinghy:

Why does epoxy resin, which sticks solidly to pretty much everything, not stick to plastics?

Its great because as I layer up the epoxy on the wood it sticks to my boat and not my tools , but before I write into Brainiac........  

Plasticiser!.......many plastics effectively 'decompose' as they age, releasing oily/gaseous products of decomposition at the surface interface.
Often, this surface 'lubricity' may be removed temporarily with acetone or other de-naturing solvents combined with the surface being mechanically 'keyed' by abrasion immediately prior to bonding with amine-epoxy/polyester-aliphatic resin adhesive.
There are also specially formulated hydrocarbon compounds which are designed to etch the surface of specific types of plastics both to remove 'bloom' but also partially soften the surface interface to permit a weld-joint to form with compatible resin systems.

[Gaffers]

so if I rubbed the plastic with solvent and scotch brite and applied expoxy it would stick?

[Debs.]

so if I rubbed the plastic with solvent and scotch brite and applied expoxy it would stick?

I`d use coarse wire-wool and give the surface a thorough roughening in all directions and use solvent afterwards (just prior to bonding with resin)....the green Scotchbrite pads are only plastic themselves so would have little abrading effect on a similarly 'plastic' surface.
Beware of using 'Nail polish remover' as a solvent; it often has oils added to prevent nail embrittlement and will contaminate your 'clean' bonding-field.
Acetone/Iso-Propanol or those alcohol-soaked pre-injection 'medi-wipes' are excellent solvents rather than decorators`s white spirit (which often has oily 'parafinoids' left in it during manufacture).

[HolyCount]

As I continue to be amazed by Debs knowledge of .....well just about everything I was pondering this question while building my sailing dinghy:

Why does epoxy resin, which sticks solidly to pretty much everything, not stick to plastics?

Its great because as I layer up the epoxy on the wood it sticks to my boat and not my tools , but before I write into Brainiac........  

Plasticiser!.......many plastics effectively 'decompose' as they age, releasing oily/gaseous products of decomposition at the surface interface.
Often, this surface 'lubricity' may be removed temporarily with acetone or other de-naturing solvents combined with the surface being mechanically 'keyed' by abrasion immediately prior to bonding with amine-epoxy/polyester-aliphatic resin adhesive.
There are also specially formulated hydrocarbon compounds which are designed to etch the surface of specific types of plastics both to remove 'bloom' but also partially soften the surface interface to permit a weld-joint to form with compatible resin systems.

Amazing how obvious the answer is, once you hear it <<Koff>>

[Big_Al]

I'm gonna change from Google to... DEBS

[dbug]

As I continue to be amazed by Debs knowledge of .....well just about everything I was pondering this question while building my sailing dinghy:

Why does epoxy resin, which sticks solidly to pretty much everything, not stick to plastics?

Its great because as I layer up the epoxy on the wood it sticks to my boat and not my tools , but before I write into Brainiac........  

Plasticiser!.......many plastics effectively 'decompose' as they age, releasing oily/gaseous products of decomposition at the surface interface.
Often, this surface 'lubricity' may be removed temporarily with acetone or other de-naturing solvents combined with the surface being mechanically 'keyed' by abrasion immediately prior to bonding with amine-epoxy/polyester-aliphatic resin adhesive.
There are also specially formulated hydrocarbon compounds which are designed to etch the surface of specific types of plastics both to remove 'bloom' but also partially soften the surface interface to permit a weld-joint to form with compatible resin systems.

Can confirm spot on!! (I have an hons degree in Plastics Technology)

[Gaffers]

As I continue to be amazed by Debs knowledge of .....well just about everything I was pondering this question while building my sailing dinghy:

Why does epoxy resin, which sticks solidly to pretty much everything, not stick to plastics?

Its great because as I layer up the epoxy on the wood it sticks to my boat and not my tools , but before I write into Brainiac........  

Plasticiser!.......many plastics effectively 'decompose' as they age, releasing oily/gaseous products of decomposition at the surface interface.
Often, this surface 'lubricity' may be removed temporarily with acetone or other de-naturing solvents combined with the surface being mechanically 'keyed' by abrasion immediately prior to bonding with amine-epoxy/polyester-aliphatic resin adhesive.
There are also specially formulated hydrocarbon compounds which are designed to etch the surface of specific types of plastics both to remove 'bloom' but also partially soften the surface interface to permit a weld-joint to form with compatible resin systems.

Can confirm spot on!! (I have an hons degree in Plastics Technology)

Reeeespect!!!  

Wanna help me coat the hull?  only 2 more coats of epoxy, a primer and paint, oh and a layer of varnish

Free board and beer in return  

 

[Gaffers]

I'm gonna change from Google to... DEBS

I'm just logging the domain www.debs.co.uk  

[Gaffers]

I'm gonna change from Google to... DEBS

I'm just logging the domain www.debs.co.uk  

D'oh! Taken  

[Mr Skrunts]

I'm gonna change from Google to... DEBS

I'm just logging the domain www.debs.co.uk  

www.debs.co.uk/help/menu/

[Debs.]

Reeeespect!!!  

Wanna help me coat the hull?  only 2 more coats of epoxy, a primer and paint, oh and a layer of varnish

Free board and beer in return  

 

  I love working with composites

Most of my working career has been with composite aircraft structure....`not much marine, but there`s a cross-over in terms of substrate, lamina and matrices between aerospace and high-spec marine use these days.
`Just love the smell of resin and sanding dust!

[Gaffers]

Reeeespect!!!  

Wanna help me coat the hull?  only 2 more coats of epoxy, a primer and paint, oh and a layer of varnish

Free board and beer in return  

 

  I love working with composites

Most of my working career has been with composite aircraft structure....`not much marine, but there`s a cross-over in terms of substrate, lamina and matrices between aerospace and high-spec marine use these days.
`Just love the smell of resin and sanding dust!

  I hope not!  Its pretty nasty stuff.  Plenty of boat builders have come a cropper as a result and many wood sawdust its not much better then asbestos..  (but why am I telling the oracle this.....?)

Not really doing substrates more a stitch and glue technique starting with 5 sheets of plywood.

This is the boat I am building :

http://www.boatplans.dk/boat_plans.asp?id=44

Upto the fairing part now, then primer then paint and varnish....

Anyone suggest names?