How weather resilient is Gelcoat
 

Hi

I’m getting close to finishing my MRS200 build and have a separate build thread underway.

A quick question for other Tribute kit owners - how weather resilient is the gel coat on the panels as it comes out of the mould? I’ve dropped a mail to Chris at Tribute as I was planning to run it for a bit when MOT’d before getting it painted but so far apart from removing the flash lines and a bit of localised filling/sanding around the rear lights and doors it’s as it came out of the mould.

It will be garaged went not being used but do I need to worry about water ingress into the GRP if it’s out in the rain before it has a base coat/primer?

Many thanks

See IanA's Z300S thread, he has been running his for 4 years and is just now getting it painted. Drop him a pm to find out the garaging conditions etc.

Very, GRP boats use gel coats as the final finish and they are obviously in constant contact with water. It is also used in making GRP swimming pools which has to be the ultimate test.

Ha ha- what garaging? It has lived outside for 4 years and will continue to do so. It is primer that is not waterproof so not a long term proposition on a steel car.

The grp surface did develop some mould like lines in the coarser sanding but regular wipes with a microfibre cloth kept that at bay whilst the thorough sanding before paint removed them completely.

TBH, the biggest problem has been condensation on the rear window so a towel lives in the well behind the seats.

My other gripe is that if it lived in a garage, I'd keep the hood down so there'd be no worries about folding the clear plastic when the temperature is low.

Thanks for the replies.

IanA - was yours in primer when you collected it from chris?

It was mainly gelcoat with some white primer covering the modifications- bonnet scoop filled, gills added, front grille recessed, etc.

Ah ok - I will probably do the same to the areas I’ve filled more to blend it into the white gelcoat on mine until it gets painted.

I’ve built kits before where the gelcoat could be polished up to give an almost paint like finish. The surface of the MRS200 panels is very rough in most areas and Matt not glossy. It is a flat surface so no evidence of the GRP matting - at first I wasn’t sure it was gelcoat hence my worry about how weather tight the surface would be.

When it comes to applying the paint, that's the important time for it to totally dried but the paint shop will know that anyway. Fibreglass is best left for as long as possible before paint, too soon out of the moulds it might show signs of sinkage and movement through the final finish. It takes longer than you think to fully cure grp.

Yes, the Rochdale Olympics that I see every year at the 1950's Specials Show developed some interesting sinkage around the bonnet hinge areas after about 40 years. Climate change perhaps?

Probly iffy materials and wobbly mould. I thought they always looked like that ?

Yes, my Sylva Fury in Oxford Blue still polishes up nicely.

I've used some rough mouldings before on some after-market Lotus Seven wings but high-build primer has been my friend, followed by lots of sanding.

The Z300S gelcoat is not shiny but I was pleased at how smooth it is and how little filling has been required overall.

Thanks IanA. Flat surfaces such as the bonnet centre section, bumper faces and roof are actually smoother than I first thought having given it a light sand at the weekend.

Great to hear the gelcoat can do the job. My uncle is looking at a Tribute project as well right after we finished installing the new rack, tonneau cover for kayak mount and a couple of led light bars for his truck.