Saturday, November 10, 2007

Further comments on the 'plastic on peel ply' technique

I've covered the other bow cap now using this technique and I am noticing in some areas the plastic lifts during curing. The resulting laminate in these areas is dry. It is curious because I am sure I have the cloth and peel ply well saturated. I suspect these are areas where I have been too aggressive with pressure on the plastic. It is a powerful technique and overall I am extremely happy with the results. Wonderful adhesion with zero air bubbles. Just a few areas that I believe I can re wet out.

I am now moving on to the larger job of laminating the decks.


bucko said...

Hi Grant , the plastic technique is fine but can have similar problems to ordinary wet-out techniques where the foam core surface is not pre-sealed ( or bog-wiped if you will ) and the temperature rises in the foam core , expands the air and bingo , a bubble . Noticed that several other builders have had bubble trouble ( ! ) and this is probably the reason , particularly when using peelply whose very close weave traps the air . Older generation foams used to have stability problems with the vinyl ester resins which caused the same thing to happen . The modern foams are far superior .Personally try and vacuum everything , then you know its right . Cheers , Jim Buckland .

GK said...

I hear you Jim,
Applying vacuum certainly makes the process robust and takes the variabilities of the builder and the materials more 'out of the equation'.

I'm still interested in exploring this plastic technique. I've seen no air bubbles. Where the plastic lifted is where I stretched it and as the resin cures the adhesion to the plastic is reduced and viola it lifts. When cured the plastic sheet almost falls off the peel ply.

I think there is a correlation between the areas where I stretched and worked the plastic too hard and the areas that are dry but not lifted from the foam. The plastic does not allow any air to get in creating this potential.

I guess it is the physics person in me that finds this really interesting. Grant

biol said...

Hi Grant. I'm following your experiments with great interest and I want to try myself in my next flat panels lamination, as I'm not using vacuum, at present.

Can you estimate how much epoxy is going into the glass, with this POP (Plastic Over Peelply) technique ? I'm around 40% glass 60% resin with my hand lamination without vacuum and this is far from the best, I'm afraid ... TIA !