Zinc barrier epoxy

[Wildefalcon]

I'm a bit nervous about asking this because I'm sure it's been covered before, and I know that I'll get a dozen conflicting bits of advice. But....

I've some old Landrover petrol tanks that I'm repairing, and I want to apply a coating that will help them survive as long as possible.

I think I need a product like Jotun barrier, followed by a satin top coat.

The tanks are poorly protected, so the coating needs to be good.

These tanks are double skinned, and rot out because it's a stupid water trap design, so a zinc rich coating that can take the abrading that a tank mounted almost directly behind the front wheel will endure is what I'm after.

I'd also like it to look half decent, so would prefer to spray the coating, rather than brush.

I've a few cheaper spray guns, but am happy to invest if that's the only way, and I'll be investing in a decent air fed mask as I can't afford new lungs.

And a gazebo, as the workshop isn't big enough for a booth.

Or, is there a better way?

 

[ajlelectronics]

You have specified a decent epoxy primer. Perhaps Jotun if that is all you are doing and brushing it, else Lechler 29107 could be regarded as superior for body parts and equally suitable for underside. It doesn't build so thickly from the gun of course.

 

[Wildefalcon]

I'm totally ignorant about these things, but I hear good things about the Jotun in marine environments, so I figured that's close to what these tanks will experience, salt on roads, mud, ethanol, petrol and all that harsh stuff.

 

[ajlelectronics]

I'm totally ignorant about these things, but I hear good things about the Jotun in marine environments, so I figured that's close to what these tanks will experience, salt on roads, mud, ethanol, petrol and all that harsh stuff.

Yes, you can't go wrong with brushing Jotun. I exclusively use 29107 because the majority of my application is sealing bodyshells via a spraygun.

29107 may be available in smaller quantities and is nicer (and designed) to be sprayed. I have some tinters in stock too if you need a colour.

 

[Dcal]

The product you are describing sounds like Jotun Barrier 80 or 90.
They are both zinc rich epoxy primers.
The Barrier 90 has 90% zinc while the Barrier 80 has 87% I think.
They both provide very effective protection when properly applied but they have a few draw backs.

Because of the high zinc content there is very little room left of the binders (the glue the makes the paint stick) so they need to be applied to a very well prepared surface.
ST3 (blasted to white metal) is best but you can get away with ST2.5. The parts you have shown look blasted so you should be good on that front.
The 90 only comes in 10l packs and as a result while they are both expensive to buy, it is possible to buy the 80 in 5lt packs, so it will "only" cost you £100+ to try. This might seem expensive but they are cheaper per litre than most single pack zinc rich primers like Galvafroid or Zinga and are far better products.
Barrier is certainly an industrial coating and it needs further coats to look good.
If it's the underside you could apply a stone chip to protect from gravel rash, but it you wanted you could apply a further coat of epoxy mastic like Jotun 87A which you could then sand to a good finish before applying the top coat of your choice.
I painted an English Wheel with Barrier 80, but I should have just used Jotamastic 87A because the frame needed a fair bit of sanding to get right and the barrier 80 did not sand well.

Another option might be to just use Jotamastic 87A or 90A. These are epoxy mastic with added aluminium for some galvanic protection (like the Barrier but much less so) and as discussed in the post above will not spray as well as a standard epoxy primer. The will however provide better protection than the Lechler.
They will also spray OK with a gravity spray gun and 2.5mm fluid tip if slightly overthinned.

"Irish" English Wheel or Wheeling Machine?

Good job, im still clearing a space in the workshop to set up welding (safety and the like). Normally just use the wee brick garage at the side of the house but as the neighbours are home now I dont want to be the noisy bugger. Not everyone can appreciate the sweetness of an angle grinder...

www.mig-welding.co.uk

 

[Wildefalcon]

Thank you, that's helpful.

Did you spray the barrier?

I'll look at the aluminium 87a stuff. It might be a good compromise between finish and protection.

Appreciate the sharing of experience.

 

[Burdekin]

Epoxy then Raptor anti-stonechip.

 

[Dcal]

Did you spray the barrier?

Yes it sprays ok if it is slightly overthinned with Jotun thinner 17 (about 15%)
By rights it should be sprayed with a huge airless setup but for areas like we are dealing with a gravity gun works fine.

Also, to work well it needs to be left full thickness so it is not really designed to be sanded to give a nice flat finish. If you want that you need to overcoat it with another primer, or mid coat and don’t cut into the Barrier. That is what I did on my English wheel, but the products I was applying over it will give a very long life on a tool that will mostly be under cover. (almost certainly longer than I have left)
Personally I'd just use the 87A, it has approvals for use in systems that will give a 20 years life in the marine splash zone which is about as bad an environment as you will get.
If you put it on clean blasted steel, don’t miss any edges or corners or sand through to the metal again it will be a bugger to get off and last very well.
A good tip is to get some tinter when you are getting the Jotun (you can get a small amount for £3 of £4) and tint alternative coats slightly different colours. You will then notice if you have missed a bit on the second coat, or if you are sanding too deep.

Link below to using 87A in a similar application.

25 year old Alfa 75 back from the brink (hopefully)

I use Dinitrol rc900 on bare steel for the same reason....basically as a rust converter and primer...then epoxy over the top. So far I've had good results.

www.mig-welding.co.uk

 

[Wildefalcon]

Thanks again. It's appreciated. I really hate doing something twice, so I want the job to out last me. Or the availability of petrol.

 

[Wildefalcon]

I have some idiot questions:

What kit do I need to do this job without making a mess?

I always end up with paint wasted when I spray. Either it doesn't pour out of the tin properly, or I mix it wrong or something.

Do I need mixing cups, or disposable buckets? What's the smart way to do this?

 

[Dcal]

For small amounts I use proper scales and mix by weight.
The paint mixing cups work fine as well as long as you are not mixing tiny amounts.
If you use a gravity gun you can end up with very little waste after a while.
However if you need to spray upside down, a gravity gun can be a pain. There are ways around it but it's best avoided if possible.

The least kit I think you need is a gravity gun with 2.5 or 3mm fluid tip, respirator, safety specs, gloves, overalls and paint cups.
I assume you already have the compressor, regulator and at least a particle filter.

 

[Wildefalcon]

Thank you, I'm going to start to research this stuff ("research" =Google).

 

[nickk]

You’ve got a jotun supplier near you,Elmbridge,in Gloucester,I use them for most of my paint.
I’m not familiar with epoxy paints though,just use their zinc rich primers,2 coats is often required.

 

[Wildefalcon]

They've been recommended to me, I'll see if they're open on Saturdays.

I've been looking at kit. I've a decent hobby air system in the workshop, a couple of belt drive compressors, and 28mm main supply to several pcl xf sockets, with drops and drains in various places.

But the spray paint side of things is a cheap crap gravity gun and a nicer copy debliss, none of which will cope with the thick Jotun.

And I've only got a battery filter 3m adfo grinding mask, for protection.

So I think I need a proper mask.


For the air fed mask I think I need something like this:

Pardon our interruption...

And a filter like this:

Deltalyo TBS4 Three Stage Breathing Air Set. Excellent value BS safe. Options for wall or bench/floor mount. (TBS4 / TBS4C) – spray guns direct

www.spraygunsdirect.co.uk

Do I need a separate filter set for the spray gun? Like this?

spray guns direct – Spray gun DeVilbiss gti pro gti pro lite flg5 pri sri, Sata Satajet 100 1000 2000 3000 4000 5000, Iwata super nova w400, az10, az3, lph80, ls400, Kestrel, Graco, Sealey, Festool, CP, Dupont, Standox, 3m and more. Free UK next day

www.spraygunsdirect.co.uk

And is this gun too cheap?

Spray Gun with Air Regulator 1.4mm 1.7mm 2.5mm Nozzle Gravity Feed HVLP | eBay

(High atomisation with low nozzle air pressure. Stainless steel nozzle and needle allows for years of trouble free use Specifications Nozzle size: 1.4mm, 1.7mm, 2.5mm). 1 x 1.4mm Nozzle. -This spray gun set is designed to provide equal atomization and partical size for all kinds of surface...

www.ebay.co.uk

I'm really sorry about all the links, but I'm really easily confused on all this stuff.

 

[Dcal]

For the Jotun you can get away without a full air fed setup, however if you are thinking of spraying 2k top coat or primers it's a useful (essential) investment.
The one you link to will use a lot of air and I prefer an air fed half mask which only uses a fraction of the air. It's just personal choice.
You will need the three way filters whatever mask you pick.
If you are running a lot of air through the regulator (spray gun and air fed mask) make sure it can provide the required flow rates.

The gun you link to is the same as the one I use for thick primers and it's been faultless for the money.
When it dies I fancy trying an ANI F/NS because they are supposed to be the best bang for your buck and you can get spares easily. I think the next gun up is essentially the same gun, just better finished.
I can’t recommend it because I haven’t tried one however I can recommend SpraygunsDIrect and have had excellent service from them over the years.

spray guns direct – Spray gun DeVilbiss gti pro gti pro lite flg5 pri sri, Sata Satajet 100 1000 2000 3000 4000 5000, Iwata super nova w400, az10, az3, lph80, ls400, Kestrel, Graco, Sealey, Festool, CP, Dupont, Standox, 3m and more. Free UK next day

www.spraygunsdirect.co.uk

 

[Wildefalcon]

Thanks for the recommendations. I'm not too bothered about the full face masks so long as I'm breathing good air, so I'll look into a half mask now. I'll contact spraygunsdirect, they look competitive enough.

Thanks again.

 

[Wildefalcon]

Email sent, I'll see what they say. Thanks again, all

 

[charlysays]

Yes, you can't go wrong with brushing Jotun. I exclusively use 29107 because the majority of my application is sealing bodyshells via a spraygun.

29107 may be available in smaller quantities and is nicer (and designed) to be sprayed. I have some tinters in stock too if you need a colour.

This is a big plus with 29107, at least one of the online paint shops decants into 1l tins. If you're doing small repairs 5l of jotun is kinda overkill.

 

[vw1]

I have used Express paints for 29107 you can buy 1,2,3,4,5ltr .

 

[Wildefalcon]

How does the 29107 compare to the jOtamastic 87a? In terms of surviving the abuse a petrol tank gets under the side of a Landrover.