11 replies to this topic

[JonnyAlpha]

Hi;

 

I'm sure I have asked this before but cannot for the life of me find my post.

 

Can someone offer some advice on the minimum timings between the following:

 

1. Epoxy Primer (Joton Jotamastic 87).

2. Seam Sealer(Ever Build Tecnic Pura Flex http://www.everbuild...ct/puraflex-40/ ) 

3. U-POL Gravitex.

4. Cellulose Top Coat.

 

 

I was going to lay another coat of Epoxy over the Seam Sealer but was advised that this was not required.

 

Found the Technical Data which says Cure Time 3.5mm 24Hours, it also says Paintability - Water Based (yes) Solvent Based (Trial Necessary), so looks like I need to let it dry for 24 Hours before attempting to chuck Gravitex over it, especially with Cellulose Thinner :-(

 

Maybe I should brush paint some Epoxy over it?

 

This stuff was recommended to me for Auto use so I thought it would be fine?

 

[Stu.]

I'd put another coat of epoxy over the seam sealer as it'll provide a sound base for the Gravitex.

 

Ever since I've been using epoxy mastics and primers I've not had one single issue with solvent reaction from celly, which I always use for topcoats. 

 

I think you might get some reaction laying Gravitex directly over the sealer, and for me it's worth doing properly and providing a second coat of epoxy to ensure you don't get any issues.

 

As for drying times, the epoxy will be dry / cured after 24 - 48 hours.

 

I'd give the Gravitex plenty of time for the solvent to evaporate, and it might soften when you lay on the celly topcoat, but as long as you leave it alone to dry / flash off it should be ok.

[crf150]

I know I'm sort of off the topic but it's the same sort of thing ! I have got a big tub of hammerite underbody seal, I was going to put this on the underside of my mini, would I be able to paint over the top of this ? With 2k ? With any paint ?

[Stu.]

Hell no.

[spiguy]

stay away from hammerite in general. it isn't what it used to be. Far better to just paint stuff then go stonechip then body colour on top of that. The hammerite doesn't do much in terms of providing a hard coat these days, and tends to react badly with everything!

[crf150]

Ok, thanks ! Will have to chuck that out then, and save up for the iPol gravitex stuff ! How many litres would I need to paint the underside ?

[JonnyAlpha]

I'd put another coat of epoxy over the seam sealer as it'll provide a sound base for the Gravitex.

 

Ever since I've been using epoxy mastics and primers I've not had one single issue with solvent reaction from celly, which I always use for topcoats. 

 

I think you might get some reaction laying Gravitex directly over the sealer, and for me it's worth doing properly and providing a second coat of epoxy to ensure you don't get any issues.

 

As for drying times, the epoxy will be dry / cured after 24 - 48 hours.

 

I'd give the Gravitex plenty of time for the solvent to evaporate, and it might soften when you lay on the celly topcoat, but as long as you leave it alone to dry / flash off it should be ok.

 

Just laid on the coat of Epoxy over the seam sealer, and was gonna sgtart the Gravitex once this has flashed? or should I leave it longer, bit of a pain if I have had to clear out the garage to spray and it looks like rain tomorrow :-(

[JonnyAlpha]

Ok, thanks ! Will have to chuck that out then, and save up for the iPol gravitex stuff ! How many litres would I need to paint the underside ?

 

You hi-jacked my thread

 

No worries, before you do anything what's the underside of your Mini like now? Has it been cleaned up? If there is any rust whatsoever then there is no point putting anything on it until the rust is sorted otherwise you would just be wasting your money.

[Stu.]

 

I'd put another coat of epoxy over the seam sealer as it'll provide a sound base for the Gravitex.

 

Ever since I've been using epoxy mastics and primers I've not had one single issue with solvent reaction from celly, which I always use for topcoats. 

 

I think you might get some reaction laying Gravitex directly over the sealer, and for me it's worth doing properly and providing a second coat of epoxy to ensure you don't get any issues.

 

As for drying times, the epoxy will be dry / cured after 24 - 48 hours.

 

I'd give the Gravitex plenty of time for the solvent to evaporate, and it might soften when you lay on the celly topcoat, but as long as you leave it alone to dry / flash off it should be ok.

 

Just laid on the coat of Epoxy over the seam sealer, and was gonna sgtart the Gravitex once this has flashed? or should I leave it longer, bit of a pain if I have had to clear out the garage to spray and it looks like rain tomorrow :-(

 

 

You really need to let the epoxy cure first.

[crf150]

Ok, thanks ! Will have to chuck that out then, and save up for the iPol gravitex stuff ! How many litres would I need to paint the underside ?

 
You hi-jacked my thread
 
No worries, before you do anything what's the underside of your Mini like now? Has it been cleaned up? If there is any rust whatsoever then there is no point putting anything on it until the rust is sorted otherwise you would just be wasting your money.

I did think I did a bit, sorry ! But I thought kill two birds with 1 stone ! I haven't got any rust on the underside, it's all been sorted, be getting paid Monday so will buy some and get on with it !

[JonnyAlpha]

 

 

Ok, thanks ! Will have to chuck that out then, and save up for the iPol gravitex stuff ! How many litres would I need to paint the underside ?

 
You hi-jacked my thread
 
No worries, before you do anything what's the underside of your Mini like now? Has it been cleaned up? If there is any rust whatsoever then there is no point putting anything on it until the rust is sorted otherwise you would just be wasting your money.

I did think I did a bit, sorry ! But I thought kill two birds with 1 stone ! I haven't got any rust on the underside, it's all been sorted, be getting paid Monday so will buy some and get on with it !

 

 

So you already have it primed?

 

I did mine in a couple of coats of Epoxy, Seam Sealer then U-POL Gravitex Plus, the Top Coat. My whole underside is Epoxied but yesterday I finished off the rear end only with Gravitex and a Top Coat of cellulose body colour.

 

The two coats of Epoxy had been left for over the 7 days curing time before I seam sealed but it could have been done sooner, on top of the sealer I sprayed some more Epoxy (only over the sealer and only a light coat).

 

The Epoxy over the seam sealer was left for a day or so then last night I laid on the Gravitex, boy that stuff can be messy, I used a Cheapo Underbody Gun from EBay (£8.99), did the trick but to get the desired effect you need about 40 PSI at the gun, an at that pressure be careful as an over zealous squeeze on the trigger will send the stuff half way over your garage, I covered everything up but some splatters still found there way where they shouldn't have .

 

The Gravitex can go on wet on wet, (about 15min between coats), and can be sprayed smooth if you use a normal Gravity Fed Gun, I tried a 1.8mm tip (biggest I have), it worked at first but in the end I had to give up as it stopped spraying, a 2 - 2.5mm tip is recommended. I ended up putting an orange peel coat on the rear valance but it looks good anyway and is pretty inconspicuous.

 

I then sprayed a cellulose top colour coat also wet on wet on the gravitex, no reaction as far as I can see and went on pretty well. You don't necessarily need a colour coat but it is recommended to help washing the mud off. 

 

Gravitex comes in three (I think) different colours so choose which you want, either the final colour or something that contrasts either your base coat or top coat to help when spraying to see where you have missed. My Epoxy was grey and the Gravitex was black, my top coat is Almond Green. 

 

Good luck

[JonnyAlpha]

Oh and Top Tip, make sure there is an Air Hole in the top of your underbody gun that screws onto the lid of your Gravitex.