Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[BarryM]

I started production of my 4'-6" hull and got as far as applying the gelcoat in the mould. At this point 'events' intervened with the result that I am not able to get at the hull to start applying the glass cloth for a couple of weeks.

My research threw up the possibility of this delay causing"shrinkage" of the gel coat. Can anyone comment on whether or not this is likely to occur and if so, what precautions I can take, if any?

Regards

Barry M

[nick_75au]

You need to put a very light layer of fibreglass, say a 75 gsm mat over the gel, then you can leave it as long as you want. Remember when you get back into it to scuff the surface with 40 then 80 grit paper.

Nick

[BarryM]

Nick,

Thank you but am I too late to put a light layer of mat on it now?

Cheers,

Barry M

[Colin Bishop]

Your likely problem is that once the gel coat has cured, resin will no longer be able to chemically bond with it properly and the additional layers of mat/resin will need to rely upon a mechanical bond. Basically this means that the gelcoat will not be stuck properly to the main hull and may come off when you extract the hull from the mouild. It may also tend to flake off afterwards too. I am not a GRP expert but you might want to consider removing the gelcoat you have already applied and starting again to be sure of getting a decent hull.

Colin

[BarryM]

Colin,

Your last sentence sums up what I was thinking but hoping against hope was avoidable. Back to square one, part the mould, clean it up, throw more money at CFS and start right over again. Oh         

Cheers,

Barry M

[nick_75au]

If the gel is still tacky/sticky then you should be ok, if its laminating gel then It should not cure fully while its exposed to air anyway. otherwise a quick sand will give some bond.

Nick

[BarryM]

There is still a slight tackiness.  Maybe hope still rises eternal.

Barry M

[Fleetcom]

If there is some tackiness then it is OK, perfectly OK. Fleetscale routinely gelcoat moulds that are not laid up on for soemtimes 2-3 days. It is not a problem.

[BarryM]

I will not be able to do anything for another week. Thus, if it still has some tackiness then, I'll carry on. If it's not, back to square one.

Thanks to all who replied. I'm much obliged.

Barry M

[BarryM]

Finally got the chance to do something yesterday which was just over two weeks since the gelcoat was applied. The gelcoat still showed a very slight tack and, hope rising eternal, I tried glassing in some surface tissue and left it overnight. This morning it showed every sign of being firmly stuck down and thus I pushed on and put an overall layer on. Looking good so far.

Fingers crossed.

Barry M

[BarryM]

To finish this saga -

I got two layers of cloth onto the surface tissue and was then struck down by the Lurgi which meant another 5 weeks delay before the final two layers could be applied over the roughened previous layer.

The moment of truth came yesterday when I sprung off the split mould and the beast beneath was revealed. A bit of minor damage on the moulded-in rubbing strakes but nothing I would put down to delays in the laminating process. The hull 'rings' sound, the gelcoat appears to be firmly attached and so I seem to have got away with it.         

Nil desperandum.

Barry M