Type of paint to choose?

[Andy8421]

This topic has been covered many times over the years, but technology and regulation moves on, and I am looking for views on the current state of the art in GRP refinishing.

I am finally starting the restoration of my '72 Sprint. I want to decide on the paint system early on, just to make sure that anything I do will be compatible with later finishing.

I have lost count of the cars I resprayed when I was young, in my 6th form years I had ran an informal car repair business, and became quite proficient at car body preparation and spraying. Cellulose paint was the only game in town, and I am confident I could still get a decent finish with cellulose paint. Cellulose does require a very volatile thinner, and I recall it would 'lift' underlying repairs as the thinner reacted with the different materials beneath the primer. I have been told GRP is particularly prone to these effects and cellulose should be avoided.

What is the current thinking on this? I want to do as much of the work on the car myself, so should I try to refinish (full strip and respray) in cellulose, or should I do part of the process (strip and prep) and have others spray in a modern synthetic system?

Any comments welcome. Thank you.

[HCA]

Yes, cellulose needs careful preparation, but never heard of avoiding it on GRP.

If you want a deep shine and have the time, just pile on the coats of cellulose and buff each one. Otherwise a one hit two pack that is used today from the likes of Glasurit!

[Grizzly]

Cellulose isn't what it once was......... since they took the lead out of it in the Uk i'd go so far as to say steer clear.

It all depends on what sort of finish you want?? and your Budget?? if you want an ultra-high gloss modern look then Water base and UHS clear is the way to go (I would always recommend the best and in my opinion thats Spies hecker, but it may be difficult to source for a DIY'r, expensive and it can be a little difficult to use outside a booth)

The next step down is Solvent base and HS clear, readily available and you can get a decent finish on it (DIY level 2k i'd suggest mobihel or lechler base with something like Lechler Macrofan 2000 HS Clearcoat or Max Meyer 0200 2K Clear over the top, cost-effective, easy to use, easy to work after and has a high level of gloss).

If you want a more original looking 2k gloss level then that would be more like a direct gloss (i'd suggest mobihel, used it before myself and it's decent entry-level direct gloss) again easy to use but slightly less room for error in the application.

Personally, i wouldn't go any lower than that..... all 2k is straightforward to put on if you have the gear and a decent size garage but don't cheap out on the top coat, it's all about the longevity!! the really cheap stuff like Prospray might go on nice and look great for a year or two but you will find it chips for fun, reacts badly to frost and has poor adhesion.....

and thats before your primers etc.......Personally, i do the grp work and seal with epoxy, block that back and load it up with Upol Reface (dry sand only, it retains moisture so you don't want to wet flat it or leave it open for prolonged periods), block 80% of it back off then seal it with a 2k high build but mixed 2-1 so it goes on very flat (almost like a wet on wet layer to seal the reface). Wet flat that back and it's top coat time....... But everyone has their own preferences regarding groundwork. I'm a little old school that a good paint job is all in the prep. If you have used old school Celullose to a reasonable level you will find modern 2k childs play.

[berni29]

Hi

I love answers like that. You really learn something.

Berni

[Andy8421]

Thank you all for your comments. Very helpful.

I will try to post pictures of the restoration, I always find it interesting to follow others doing the same. The pandemic has slowed everything down, I needed to build a new garage to house the garden machinery so I could use the old garage to house the lift, discovering the old garage needs a new floor, and then a new roof, and so on and so on. Hopefully the new floor will be complete and lift installed by Christmas.

The link below sums it up well.

https://www.youtube.com/watch?v=v1dvAxA9ib0

[UAB807F]

Great post Chris, very interesting to hear how much things have changed in the paint department.

Brian

[Grizzly]

Just to add........ if you do use an Epoxy to seal your GRP work it's important it's FULLY cured before putting anything over it.

Epoxy primer is hands down the best barrier coat out there, doesn't shrink or sink, and has the best adhesion etc but be warned!! it has a waxy film on the top as it dries especially in a diy home garage environment and if that hasn't gone before you start to work it you will run into problems down the line.