Rubbing down gel coat

SDMC001 · #1 14th July 2007, 18:20

I have over a few weeks been rubbing down the flash lines, and many scrateches supplied. What is the experience of previous folk, as although I seem to have a good polished finish, there are scratches where I have rubbed down that I cant shift.

Thanks Steve

alackofspeed · #2 14th July 2007, 19:57

Steve,

This is slightly off topic, but have you found yourself rubbing through the gelcoat to smooth out the flash lines?

I'm spending ages at the moment trying to sort my bodywork, but it's driving me nuts, as the gelcoat is so thin I can't help but keep rubbing through it

.

John.

Ex-Biker · #3 14th July 2007, 21:01

You need to ensure you have got rid of the flash line before 'polishing up'.
It could be that there was still a little of the line there.

I also had a few problems where the gelgoat was very thin in places. With a little help, I was shown how you rud a groove in the fibreglass and back fill with new gel -then back to rubbing down again.

SDMC001 · #4 15th July 2007, 06:48

John

Firstly yes, the gel coat seems very thin in some places, almost non existent, so yest I have rubbed through it several times, which I am getting iritated by.

Ex biker

But my main problem is, after rubbing everthing down, I still have small scratch marks that I can see after polishing. I dont seem to know where to stop finishing with 1000 grade paper to avoid them.

I did not expect to overcome this problem over night, but afer all the hard work building the car, I am now concerned it will be let down by the finish.

Steve

Ex-Biker · #5 15th July 2007, 19:53

Steve

Try using a rubbing compound, followed by a T-Cut, if you can with an buffer.

alackofspeed · #6 15th July 2007, 20:10

Steve,

Did you get any gelcoat with your body panels? I did, and it's really saving the appearance of my panels. Tedious process though - dremelling out the deficient area, dabbing the gelcoat in, cutting it back.... hopefully it'll pay off!

The areas I've repaired so far, I've cut back with 200, 800, then 1200 grit wet 'n' dry, then g3 cutting compound. Even by hand, this yeilds a fairly decent appearance. Hopefully it'll be better still once I've bought a polisher.

Good luck with your quest!

John.

bigrich · #7 19th July 2007, 19:37

Hi Steve,

No alternative to elbow grease I'm afraid.

400 - 600 - 800 - 1200 - 1500 wet n dry (don't forget to put some washing up liquid in the water...helps the process along)

...I used the sailboats GRP system (cutting polish designed for boats - which are gel coat f/glass)...works loads better than t-cut and auto products that are designed for paint.

www.sailboats.co.uk - 3G compound, then cutting boat polish, then carnauba wax.

...let me know how you get on...around 50 hrs should do the trick!

ATB

Rich

alackofspeed · #8 19th July 2007, 21:48

Rich,

I know you did a fantastic job with your gelcoat, but I'm simply amazed how few issues you had with polishing through the gelcoat. I don't know if Steve is suffering like me, but there are few flash lines I've managed to scrape back where I haven't gone through the gelcoat long before the flash line is anywhere near flush!

I don't know how long it's going to take me to get my panels presentable, but I think I might go potty before I reach a decent finish

.

Cheers,

John.

SDMC001 · #9 20th July 2007, 15:12

I tried another method today on the bonnet, after getting rid of the flash lines, then useing 1500 w/d with wet with compound, then finish with T cut. Seemed quite good, so maybe use this process from now on.

Do a few hours at a time, then either my shoulder na delbow give out, or boredom sets in.

Steve

alackofspeed · #10 19th December 2007, 12:19

Steve,

I just revisited this topic, as having had a crack at my bodywork a few months back, I'm now revisting it. How good did you get your car's finish in the end?

I'm going to have to resort to some discretly positioned adhesive black vinyl on my car, as the gel coat is simply diabolical, and the areas that need chasing and refilling with gelcoat too vast.

I think I've done a respectable job of the mechanical parts, but the bodywork is really letting the side down. I'm not sure a spray job will remedy things, as the GRP flexes so much, I can see the paint cracking.

Cheers,

John.

SDMC001 · #11 19th December 2007, 12:52

John

I really just carried on a said in my last comment, although, I did take the front clam to a GRP specilaist who done some repair work on it, which I must say does look nice. His comments were not very complimentry of the finish qulaity of the body work, and after seeing some ohis work I undsrstood why. I did buy one of those polishers which does seem to help. Every time I wash the car now I polish it with Blue stained T cut, which slowly is getting a nicer finish, albeit I still do see the scratches in certain lights. On the face of it I am not happy with the finish, just accept the worst of a really poor job.

I do empaphise with you, and if like me you have ever suffered with tennis elbow, dont over do it like I did, as a few weeks after the finishing polishing, it reared it ugly head.

Steve

Jon@JNRacing.co.uk · #12 19th December 2007, 13:51

My Body is thin, ok its a race body so is light but the bodyshop that is doing the new design said how poor the finish was. The body is only fibreglass mat which isn't that strong.

To save wieght the new body for my car is going to be Kevlar rather than fibreglass mat, the gelcoat finish will be a lot better than the standard Marlin supplied body as mine will be a 4 piece complete kit rather than being made in 8-10 different sections then being stuck together.

bigrich · #13 19th December 2007, 20:12

Jon,

I thought you had reached the end of the road and it was all up for sale??

How come you're back on building bodywork?

Rich

alackofspeed · #14 19th December 2007, 21:26

Jon@JNRacing.co.uk · #15 20th December 2007, 07:53

Im still doing the New Body Design as I could still sell them once I have the moulds

But cant say too much at this stage on what really is going on

eaa53 · #16 21st December 2007, 17:05

This web site may help a little. http://www.polishedbliss.co.uk/acatalog/guides.html

It’s based on paint finishes but covers all sorts of cleaning and polishing products and techniques. The painted surface is less forgiving generally.

Different guided relate to different areas of interest, one covers just cleaning alloys and protecting the finish once clean for instance.

I thought I knew how to wash a car until I read the advice on this site.

Further to all that, it explains about swirl marks and how to remove them and the different types of finish you can achieve with different products on the same surface.

Regrettably this site cannot help if the raw material is sub standard.

It may help you understand the options if nothing else.

JohnC

alackofspeed · #17 25th December 2007, 22:37

Well, I decided I'd had enough of trying to repair the gelcoat, so decided to chance my luck with a gloss black Halfords rattle-can....

So far, it appears to be a fairly respectable match, and even if it's not perfect, it's certainly MASSIVELY better than the finish I was getting with gelcoat repairs (gelcoat colour wasn't consistent).

The pic below, was taken after I machine cut the surface back, and hadn't been polished, so it's slightly matt.

5EXi girl · #18 5th January 2008, 18:13

We accept that there were some occasions when a small number of bodies were highlighted as having less then perfect gel coats. This led us to searching for and appointing a new supplier. The new supplier has agreed that they will be much more accommodating should any problems arise in future. These bodies are made as light as is practically possible without the use of more expensive raw materials such as woven mat, carbon fibre, diolin or other more exotic materials. This ensures that our customers receive maximum value for money and will be able to afford the repairs if any accidental damage occurs! As we have previously stated we particularly make a racing car body as light as possible which probably weighs less than half that of the production car bodies. This helps to ensure that the race car bodies are as light as possible, all of which aids competitive performance.
Kind Regards
Terry and Mark