Spraying Pre-Cat.

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JimmyC

New User
Jimmy
Hey all,
I have a few questions about spraying white paint for a project that I may have coming up. I have decided to give Mohawk pre-cat a try, using the primer first, followed by white, followed by clear.

What is the best spray system, that's not too expensive(I'm trying to stay under $400), to use for this medium.

Also, what would the coverage be for a gallon of white as I am planning to shoot a couple of cabinets.

Thanks in advance.
 

FredP

Fred
Corporate Member
I've sprayed that with a PC HVLP conversion gun.[100 bucks] it drys too fast.:cool: I went back to non catalized and get a much better finish. the pre-cat was rough because it didnt have time to flow out. and its hard stuff so rubbing it out was tough. retarder helps. BUT [there is always a but] you can always get jeff mills to come put some magic spit on it!:rotflm: worked on mine!:gar-La;
 

Robb Parker

New User
Robb
Jimmy, Mohawk is a good product, used till 5 years ago when moved to NC. Switched to ML Cambell products due to no Mohawk dealers in this area and shipping is to much $$$ on solvent products now. Check to see if Wurth wood Group in your area for Campbell products. That said, you can get good results but viscosity and tip size are very important.

You'll want only 3 coats at +- 5 mil wet each with pre and post cat. Clear is un-necessary with precat and not recommended by mfg dry mill too thick. Get primer tinted. With the "burn in" of lacquer products, the clear will not be anymore protective than without. If it chips or scratches the layers act as one. Get a mil guage, easy to use and cheap, 4-5 mils is thicker than you think but essential, (Can you say "It's gonna run!") Spray horizontal if possible. Sample boards are important and keep record of ounces of thinner/product.

Your sealer is going to be 50-55% solids, it usually will have to be thinned to spray. Mfg will probably recommend 10-15%. It's not a problem to go more to get good atomization. Lay it on WET. It will dry to sand in 1-2 hours. Sand with very fine, we use sanding blocks by hand. your only trying to get snots knocked off (hopefully you won't have any) and etch for further coating. Try not to sand thru sealer. If you do, lightly recoat only sand thru and scotch bright. Lay on 2 coats of white pigmented finish. We use satin 15-25 sheen. Use maroon scotch bright or 3m between coats (etching only). If you end up w/ Cambell products we use Clawlock sealer and either Resitant or Krystal finish coats. However, both are post cat but mixing is not a problem. Get a ratio cup no matter what system your using. As far a coverage, too many variables, transfer rate, over spray etc but you should easily get 1-300 sq ft per gallon or in you case 2-4 or better cabinets w/ doors and drawers at a minimum.

Guns! Lots to choose from and the old saying "you get what you pay for". In the 2-400.00 range will get you a very good gun though. Would recommend buying from auto supplier, Wurth, Mohawk or possibly from finish house online. I say this because they will have a tech rep that can recommend/ help with tip sizes, set up etc. All sizes are not standard and vary by gun mfg. Some good guns Sata,Defilbis, Binks,CA technoligies Kremlin etc. We use Sata air assist HVLP gravity feed w/ 1.4 tip for most products.

Again experiment with sample boards. Once you "master" (I'm still learning after 25+ years) these finishes you'll never go back. Many options for finishes, glazes, sand thrus, distressed etc. There is a learning curve though, but it's not that painful.

If you need further help contact me.

Robb
Heritage Woodwright LLC
 

dino drosas

Dino
Corporate Member
Robb, Thanks for all that good info. I've been using Mohawk pre-cat products quite a bit lately and still learning, but I'm slowly getting there. I have been getting it from Klingspor's Woodworking Shop; and with the NCWW discount it is priced right. Another nice thing is that they carry all the various Mohawk products in aresol cans for the small projects. These really come in handy.
 

CrealBilly

New User
Jeff
Spit sand with 600 grit in between coats , followed by a wiping with tack cloth. I know spit sanding sounds nasty but works better any any sanding lubricate I've ever used, plus it's free. Final coat should be scuffed up with 0000 steel wool, long straight strokes with the grain then buffed with a bonnet and automotive buffing compound something Meguiar's Mirror Glaze works well. Don't wait to long in between coats Pre-Cat dries in a hurry.
 

JimmyC

New User
Jimmy
Everybody, thanks alot. Robb especially you for in depth explanation, I do have a wyrth group in Raleigh as well as a Klingspor so I'll have to choose one.

I would like to go with an HVLP sprayer, but I have to check them out. About 20 years ago I did production spraying for an aerospace subcontractor and use a Binks model 70 auto gun, spraying on no more than 3 mil thickness. But it's been so long since I've sprayed that it's like starting over.

As far as a top coat goes, the main reason I was thinking about spraying one is for a semi gloss/satin finish, because I don't want the finish too shiny.

So far, thanks all.
 

Tarhead

Mark
Corporate Member
Jimmy,
I also used the ML Campbell Resistant pigmented white over a coat of Clawlock on my kitchen cabinet rehab. The Wurth paint shop was able to match the color and the gloss level I needed. I did need to go over everything with a grey scotch pad to get rid of some bumps from the overspray. It is truly a tough finish for a kitchen cabinet and worth the premium price. I'm climbing in there if we ever get nuked:rotflm:
 

Robb Parker

New User
Robb
Fred- Assume "drys too fast" your refering to off the gun tip and not dry to touch after spraying. Dry to touch is key in a finishing room enviroment, little contamination ie dust and can handle/sand quickly. Usually we can completely finish a project in one day assuming not too huge. If your refering to out of gun tip, several suggestions. Open fluid adjust knob almost full open, 3/4 to full fan on fan adjust then throttle air adjust down till you are just getting full atomization. Play with thinning material, and gun tips. Go slow and lay down a fairly thick coating of material, like I said 5mil wet is almost to the point of sagging on verticle, easier on horizontal. You should not however go over 5 mil as most mfg only recommend this thickness wet which will dry to around 2-2.5 dry.

Dino- Like I said used Mohawk for years mostly nitro-cell lacquer. Didn't know Klingspor carried Mohawk. Guess I'll have to check thier prices. I mostly use post cat because of shelf life of un-catalized material. Used many of their "touch up" kits and aresols in field. They have the most extensive touch up selection I know of. Good web site many products. I spray 20-30 gals of Campbell product/mo. I pay average 27-32.00 per gal depending on product. You should try Campbell's post cats. Really pretty painless mixing in their ratio cups. Incredible durability!

Jeff- Only time we sand wet is for gloss finishes 75 sheen plus. Mostly for leveling as no amount of pre sanding will get level enough on raw wood/mdf. We regularly seal/prime them sand the next day no issue. Same sanding, If we sand too quick though before fully dry +-1 hr for post cats, it "gums" our paper. Same with buffing final coat only on glosses. Not sure why you'de need to as my off the gun finish is pretty slick furniture grade finish. But as has been said your method is magic but sorry I'de have to wear gloves to use your spit:rotflm:

Jimmy- As Tarhead said, any of Campbell's, or Mohawk for that matter will tint and sheen to your specs. Satin is my finish choice for 90% of my work. Tinted is same formulation as clears, only pigmented. When you say HVLP, I don't know if you mean turbine or gun driven off compressor. I tried 4 stage turbine hvlp and didn't like it! Steep learning curve for me and HEAVY hose 1.5" diameter. They have their place I'm sure but like you I sprayed conventional for years. Quite a transition for me, too much so. If you get a simuliar gun to Binks gun you had you'll be more comfortable, I think(I sprayed them for years and still have them if anyone wants them). Now prefer gravity feed compressor driven w/ 3M disposable over cup. HVPL to me is only an advantage when spraying inside a cabinet in the 3 corner area, overspray on other panels much less. We currently leave the backs off and spray seperately even with HVLP.

Your having sprayed before you'll have no trouble laying down nice finishes. Like riding a bicycle or sc....., never mind you get the picture.
You'll have no problem picking it up again as you have the technique already, same as spraying planes, autos or cabinets. Only different materials and laying down different mils. I'm with Tarhead though, don't shy away from post cats- great finishes.

Robb
 
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