fibreglass matting to plastic

[easyrider]

Hi i am currently making a new canopy for my boat using a hardtop roof and a canvass wrap around. I have made the roof using timber and upvc soffit boards. I now want to put a fibreglass covering over the top of it but not sure how to stick it to the soffit boards. Would the resin that comes with the matting work or do i need a special glue/resin. Thanks for any tips

[JawsOrca]

Hi Jim.

 

I'd use an epoxy resin: http://www.ecfibreglasssupplies.co.uk/c-1004-resins-epoxy.aspx(Polyester may peel off.. although not sure even epoxy will stick to UPVC.. I've never used such material.. You probably want Ply although I can't quite picture what you are doing... have you got some pictures?)

 

Also I'd use a cloth and not a matting as it will look nicer (http://www.ecfibreglasssupplies.co.uk/p-1707-glassfibre-cloth-48g-x-1-mt-wide.aspx).

 

[easyrider]

Hi jaws thanks for quick response. Below is a rough diagram of what ive done. What i want to do now is fibreglass over the soffit boards to add a bit more strengh to it whilst keeping the weight down. This is why i used soffit and not wooden boards as its a lot lighter

[JawsOrca]

Pleasure Jim.

 

I highly doubt resin will stick to the plastic (plus if it's plastic there's probably no need as you will only coat it to protect and prolong the life. I'd say go with ply (4 or 6mm should curve) and then coat that.. or do it with some nice timber and coat with varnish it should come up really nicely. 

 

Good luck.

[ranworthbreeze]

Hi Jim,

If you are going to use ply, I agree with Alan it may be the best way to go, I suggest that you do use a exterior grade or marine ply so it does not delaminate.

Regards

Alan

[DaveRolaves]

The UPVC needs to be replaced with marine ply - 6mm would be fine. Once the roof has been finished completely in wood give the roof a coat of fibre glass resin all over and then apply and roll about 4 layers of 600 gram fibre glass matt over it- this will give a fibre glass sheafing of about 6mm onto the roof. The finish can either be painted after the GRP has cured well or you could coat it with a coloured flowcoat.

[Oddfellow]

Much of the advice given is sound.

 

Be wary of trying to put a gel finish on it. It can be awkward stuff to work with in large areas as you will need to get it flat and then polish it.

 

This is far from a quick job.

 

Instead, you might consider using a tissue as the final external layer. The job of the tissue is to smooth out any GRP strand markings and will make smoothing the job much easier, ready for painting.

[C.Ricko]

get rid of the upvc and use wood, epoxy sheath, use a peel ply on the last coat of west and paint with 2 pack. 

good job done.

[MBA Marine]

Or you use my clever little pal the roll of parcel tape, tape over your UPVC, make sure it wont flex underneath the lay 2x 600g of chop strand on, once cured another 2x 600g, once cured peel it off the roof, remove your upvc and put your roof shaped GRP panel in its place, bond in place over and down with a further 2x 600g  topped with tissue. Hey presto a strong roof without any of that horrible wood stuff that likes to rot out, buzz over with the sander and paint.