hvlp apllo spraymate vs compressor and gun

[Skilli]

Hello,

First off, this is my first car restoration attempt and at every step I have had to learn how to do things for my self with the help of books and from good people such as yourselves on internet forums. Second thing, all the wok on my car has been completed outside under a shelter.





I spent 2 years welding my mk1 golf. I then painted the shell in epoxy using an Apollo spraymate. The finish is not good. Despite thinning the epoxy to the maximum recommended, the paint has not atomised very well and the finish is very rough...like 40 grit sandpaper. I thought that I would flat this back and then paint with a high build primer from builthamber and then flat back ready for a pro to paint on the colour coat.




However, I’ve had to flat the epoxy back so much that in places I’ve gone back to steel. Being outside, this then needed another coat of epoxy using the Apollo spray mate and then I’m back to square one. I’ve tried using a gloss roller but they disintegrate quickly and leave bits of foam on the finish.

I thought about getting a better HVLP Apollo kit but £330 is more than I want to spend on a paint system for possibly only on restoration.

http://www.hvlpshop.co.uk/Item/apollo_prospray_1500

I have now decided that I will have to buy a compressor and a gun to get better atomisation but what to buy?????

Bottom line is, what is the minimum I need to get the job done???

I saw this US website and they suggested bare minimum get an LVLP gravity gun requiring 5-7 cfm with a 20-30 gal, 1.5-2hp compressor.

However, will this be sufficient???

http://www.spraygunsdirect.co.uk/product.php?tid=180&products_id=6799

All for under 200, all I need is the gun (probably another minefield). The the cfm seems sufficient (6.8cfm) but it only has 24 litre tank and 1hp motor

Any thougths would be greatly appreciated.

 

[FranV8]

Well done for sticking with it. I think you'll find your compressor will struggle, it's only really putting out about 4.5 cfm fad. You're best using a regular gun rather than HVLP in my opinion. Someone who actually knows what they are talking about will probably be along in a minute to give more detailed advice.

 

[tlovatt]

Which Apollo are you using at the moment?

You do sometimes need to thin down paints more to use a HVLP system than a high pressure system. The finish you can get from an HVLP system should be similar to a high pressure system and it should not be rough if done properly, I would suggest you have a bit more of a play with your current setup on some scrap and see if you can improve, if the finish is that rough you could have feed problems or you could be holding the gun too far away?

 

[Skilli]

I'm using the cheapest apollo, the spraymate.
http://www.hvlpshop.co.uk/Item/apollo_spraymate

I went for this because I only wanted it for primer and assumed (after some internet research) that it would be sufficient to provide an adequate finish for flating back and then get a pro to put the final coat on.

This spraymateuns at 3psi next model up at 4psi (apollo 1200 = £200) and the appollo 1500 runs at 5 psi. The sparaymate comes with a 1.8mm needle but the 1200 and 1500 are fitted with 1.3mm needle. What might this mean for atomisation?.

Im using rustbuster body epoxy 421. It suggests 20% thinning max. Can I go higher than this?

 

[tlovatt]

I have never used one of the base model units, I have used a 800 series (now replaced with the 1500 series) and I have a 1200 unit that I use for spraying a number of substances (varnish, paint, lacquers etc). I have also used the 1200 to do respray a couple of body panels.

Given the choice between my HVLP system and a conventional high pressure system I would chose the HVLP every time (less paint inhaled and bouncing off onto everything else).

I would suggest you try thinning a little of the primer down further, adjust the spray pattern and distance from the item to be painted - practice on some scrap. Using a base model system I would expect it is possible, but will be slow (and if you try and speed it up will get a bad finish). The advice on the primer will be aimed at high pressure systems.

 

[marlinspike]

I am not sure that kit is good value at £200. The compressor in it is the same size and cfm as my £90 Aldi one - they are the Thursday special starting next Thurs by coincidence. It will probably power a spraygun but it won't be strong enough to power air tools. I haven't sprayed with mine yet but was planning to buy the mini spray guns from ebay to do a few bits. Not sure you could do a whole car with 7cfm, unless you did a panel at a time.

If your budget is £200 there are probably better buys. Register with Machine Mart and they will start sending you money off vouchers after a while.

 

[tlovatt]

I am not sure that kit is good value at £200. The compressor in it is the same size and cfm as my £90 Aldi one - they are the Thursday special starting next Thurs by coincidence. It will probably power a spraygun but it won't be strong enough to power air tools. I haven't sprayed with mine yet but was planning to buy the mini spray guns from ebay to do a few bits. Not sure you could do a whole car with 7cfm, unless you did a panel at a time.

To compare with a compressor you would need to look at the free air delivery, not the displacement volume, you can also not spray a car using a mini gun and expect and reasonable results.

The spraymaster 1200 and 1500 are suitable for continuous spraying and completion of complete cars with a good finish unlike small compressors, they work without and significant variation in air pressure (unlike small compressors) and due to the lower pressure provide much greater deposition rates - if you are using 2k paints you should have a suitable breathing filter, but it is still better to have less paint in the air.

But as before, the OP should have a play with some scrap panels of surface and adjust the thinning of the primer and distance between gun and target and feed rate to see if he can get it to work - I suspect he will be able to.

 

[Skilli]

Thanks for all your comments.

So the conlcusion seems to be that compared to a small compressor, the spraymaster is superior for the home diy guy. The Apllo 1200 and 1500 might be better than the base model but I should be able to achieve an adequate finish with what I've already got. I will not be spraying the entire car at ones but panel at a time.

I've found an old picture that shows the paint surface (ignore the rust spots, this was my first attempt and it has since be redone).


Can anyone tell me about the effects of different spray patterns and flow rate?
You can rotate the nozzle on the sparymaster to give you a horizontal oval or a vertical oval, I dont think it enables you to change the width of the oval.

The flow rate is controled by allowing the needle to go further in when you pull the trigger. What effect does this have on atomisation. I would assume that the further the needle goes in then the worse the artomisation would be.

What about distance from the surface. I'm assuming that closer to the surface will give you a smoother finish but you have to movet he gun faster to prevent runs.

I have been spraying with very low flow rate so I might try raining that for starters and moving more quickly .

 

[dsj1979]

After reading this and many other Apollo turbine reports I'll be buying one, the 1500. The gun which comes with it has good reports but you can buy without a gun as well. My thoughts at the moment are to have the existing package with anb300 gun, upgrade to the 7500 or buy a few cheaper ones. Depending how many jet / needle kits are required that part could get pricey!

 

[richie00boy]

Have a go properly setting up what you have got or you may just have the same problem. You said you had a very low flow rate set, that's not what you want, you want a decent flow rate to get good timely flow out of the material and good build.

I bet if you thin the paint a lot more and up the fluid delivery you will have much better results.

 

[tlovatt]

Looking at the picture you flow rate is too low and I suspect you may have the gun too far away, you need to adjust the flow rate so that you are achieving good coverage at the speed you are moving and ensure that the paint is not drying too much before it hits the surface to be painted.

Thin the pain down a bit more (you should have a viscosity pot that came with the sprayer, use this to get the mix correct until you get a feel for it), set the pattern to be a fan at 90 degrees to you gun travel, normally apply a coat with horizontal movements and then a coat with vertical movements to get even coverage. The circular pattern is for work in corners as opposed to surface spraying. Just keep practising on some scrap and you will get there.

 

[Daz1968]

Anyone know if one of these would paint 2k high build as I can only run a mini gun with my airfed which is ok for top coat but don't want to use it on primer if I can help it,

 

[tlovatt]

Anyone know if one of these would paint 2k high build as I can only run a mini gun with my airfed which is ok for top coat but don't want to use it on primer if I can help it,

Which Apollo model are you asking about?

 

[Skilli]

Thanks for all the advice. I have recindled enthusiasm for the apollo. Lookign mforward to having another go. I'll post an update

Here is the viscoisty chart that came with the sprayer. Could anyone tell me what kind of paint epoxy most like? I've use emulison before in my house but non of the others.

 

[tlovatt]

Aim for around 24 seconds and see how you get on as a starting point, keep the spray gun around 6 inches (150mm) from the work piece, may your passes parallel (i.e. be careful not to vary the distance from or angle to the workpiece) and play with the flow rate. If you are inexperienced with spraying you will probably find that the correct flow rate results in a few runs in the paint until you get the hang of it, insufficient flow rates will cause a number of problems.

You can also have a look on youtube for HVLP videos to get some ideas on setup and gun speeds etc.