Adhesive question

[Yertis]

Not really sure where else to ask this question so I thought I'd try you lot first. I'm finishing a GRP column switch cowl for my TR6 (I've replaced the old-fashioned floor dip-switch with a column switch etc – it's a Revington TR mod) The GRP is good and strong but the perfectionist in me means I'm taking it a bit further using ABS bits and pieces so it looks more OEM. Old vac-form model assembly techniques are being dragged out of the recesses of my mind.

Anyway, I need to attach some braces, cut from ABS, to the inside of the cowl. What is going to be the best adhesive for ABS to GRP?? Araldite? Isopon filler? Araldite then build up around with Isopon? Or is there something else especially for this kind of thing?

All advice welcome!

[Equus]

I'd go for PU Adhesive - something like Tigerseal

[GliderRider]

Stabilit Express is what Graupner (a German model manufacturer) recommended for ABS parts in their kits. One part is a powder, the other liquid. I've only ever seen it sold in Lidl.

What ever you use, key (roughen) the surfaces on which the adhesive will be extremely thoroughly with emery cloth, and don't touch the keyed surfaces once you have done so. Fingerprints make a good release agent! If you do get finger prints on anything, clean the surfaces with Isopropanol or methylated spirit.

If you use epoxy, the 24hr stuff is stronger than the faster varieties.

[Yertis]

Thanks both.

I'll try Stabilit Express or 24 hour epoxy. Reading up on the PU it seems better suited to applications with different requirements. Most importantly, works best with fine tolerances which won't be possible on the non-gel side of GRP. Good to know about though.

I'll let you know how I get on!

Ta.

[Equus]

Yertis said:

Reading up on the PU it seems better suited to applications with different requirements. Most importantly, works best with fine tolerances which won't be possible on the non-gel side of GRP.

Just the opposite, I'd have said - which is why I recommended it. It sticks well to ABS (which epoxy usually doesn't, even when keyed - it tends to peel very easily from ABS or other hard plastic surfaces), and it is tough enough to have excellent gap filling properties.

It's frequently used to bond GRP or aluminium body and trim panels to steel chassis on kit cars. Ask on the kit car forums if you're in any doubt as to its toughness and stickyness.

[dr_gn]

Equus said:

Yertis said:

Reading up on the PU it seems better suited to applications with different requirements. Most importantly, works best with fine tolerances which won't be possible on the non-gel side of GRP.

Just the opposite, I'd have said - which is why I recommended it. It sticks well to ABS (which epoxy usually doesn't, even when keyed - it tends to peel very easily from ABS or other hard plastic surfaces), and it is tough enough to have excellent gap filling properties.

It's frequently used to bond GRP or aluminium body and trim panels to steel chassis on kit cars. Ask on the kit car forums if you're in any doubt as to its toughness and stickyness.

It's the same kind of consistency as silicone sealant from what I've used (carbon fibre to ABS and Nylon) - it would be great for gap filling and bonding applications.

[Equus]

dr_gn said:

It's the same kind of consistency as silicone sealant...

Indeed - but much stickier and rather stiffer when cured.

The main downside is that it can be messy if you're not careful - it's magically attracted to the best clothing or fabric surface in the immediate vicinity.