easy Nitro proofing wood hulls??

[tremors]

Hi,

I just about finished building my first wood tunnel hull. Now I need to paint and fuel proof it. basically I'd like one simple color, nothing too fancy. I'm looking kind of looking to do it an easy way because my "workshop" is basically my kitchen table (of course I'd probably be painting it outside).

Anyway, after toying with a few ideas I was wondering if I can use the automotive touch-up paint in spray cans. Would this work? Primer/sealer, paint, and then clearcoat?

Any and all ideas would be greatly appreciated.

GREAT FORUM!

Thanks, Geno

 

[TomMoorehouse]

tremors... well i wish i had an easy answer for ya.... i researched like mad to find something that was easy/cheep/widely available/ not too toxic.... cant find anything.... the automotive touchup definately wont work.... you need actual automotive paint (this is the best solution).... or some type of epoxy paint.... most hobby shops will have pactura formula U paint that works ok... but dont let nitro set very long on it or it will be ruined.... if ya can find any.... get K&B super poxy or hobby poxy.... it works great..... youll need a spray gun for it though.

last resort.... get the epoxy appliance paint (from home depot and the like) it will hold up simmilar to the pactura formula paint..... youll find it in white, lt brown, and black likely

hope this helps

tom

 

[tremors]

Will the K&B ultra poxy or regular Auto paint shoot well enough with a regular paasche type air brush?

 

[TomMoorehouse]

i have used the ultra poxy with the larger type of airbrushes.... cant remember the exact one..... it was that cheepie you can get at most hobby shopy.... i think it was a badger.... it worked ok.... it was just a pain cause it kept clogging

 

[Flying Pilgrim]

Primer does not matter much unless you are using a butarate (sp?) based paint Remember this: Test First!!Depending on your nitro content, you can get away with formula U paint or LustreKote. Formula U takes a long time to dry, LustreKote is only good for up to 10 or 15% nitro plus takes a long time to cure. Your best bet is K&B epoxy paints or one of the two part automotive paints. If using the automotive paints, still test it for nitro resistance.

 

[shoboat]

Just go to your local bump shop and have them paint it.

It is easy.

Thanks,

Mark

 

[Jerry Dunlap]

Having build a few wood tunnel hulls, here's a few suggestions:

1. I coat all my wood hulls with West Systems Epoxy. However, unless you plan to build lots of boats this is rather expensive for just one boat.

2. To seal the wood, spray on a couple of coats of rattle can automotive clear. Sand lightly between coats.

3. Then spray rattle can primer on the hull. I think Krylon Brand White Primer is the best.

4. Once you spray the boat with primer you will probably see cracks and areas that need filling. Automotive body putty works great for this and spot and glazing putty fills small blemishes.

5. Sand the boat and primer it again to cover the body putty.

6. Do a final sanding of the primer with 400 and apply a color coat. The rattle can epoxy paint for appliances is a good paint and you can add lots of peel and stick decals.

7. Other automotive rattle can paint colors can be applied and then covered with a rattle can clear like Formula U or Lustre Kote Crystal Clear.

I'm a big rattle can fan.

Jerry Dunlap

 

[Hammerhead]

If you are interested in a cheap good way to get a nice finish, you need to contact MikeP about his epoxy paper towel wipe on method. Works fantastic, and it is not messy or stinky like sprays are. Just thinking about you doing it inside your house, bud. Give him an Email. He will be more than happy to help you out. You will have to do the color outside, though.

Hammer

 

[jklimpel]

Nitro-proofing is a relative term.

A finish that can endure 10% all day long, may only last a few seconds with 45% spilled on it.

What you finish a hull with also depends on where you do your work.

Working on the kitchen table (or even in the house) will prevent you from using the best (albeit the most toxic) finishes.

For 20% or less..and if you dont want to use a clear coat, any single stage auto finish will do. (Even some of the better varsol based finishes will work) Be careful using acetone based paints over varsol based finishes! (Will lift it off just as fast as model fuel)

For 20%-40%, some of the better single stage finishes will do, but make sure you test it first before investing all the time/effort just to have the paint stripped off.

Anything over 40%. (This is where most boats run)

1. You can use an epoxy based finish. They provide great looking results, but it will be very difficult to remove/repair/blend any blemishes once complete/cured. Also, they cannot be stored once mixed, and you have to clean your equipment very well, immediately afterwards

2. You can use an Automotive Urethane based clearcoat. (My preference) This stuff is great!! although it is super toxic. (See my warning below) Make sure you use the professional stuff from your local auto/body parts supply shop that requires hardener! (approx $70gallon for good stuff)

When you buy it, the dealer will tell you that you need to apply 'base colour' paint...and will then try to sell it to you. Don't bother.

You can use almost ANY kind of paint as a base coat. (Aerosol, varsol based rust paint, latex etc)...just let it cure for a few days before applying clearcoat on top. When applying clear, allow 15 minute 'flash' times between coats. Use what you mix within 30 minutes, or it will start going on thick and you will get an 'orange peel' look. (You can sand it out later.....but easier to avoid altogether)

Another nice thing is how easy you can repair/colormatch damage to a small part vs. repainting the entire model...it is very forgiving.

Don't clearcoat anything you don't want to have a super-shiny/mirror like finish. (You can get 'flat' clear if req'd)

-My personal preference is using varsol based finishes as a base coat. (Tremclad etc) It is very cheap and easy to thin out/apply..and not too toxic.

If you are painting a metal piece, make sure you use an etching primer before your base coat, or it will chip off with use. The extra $ needed for the special primer will make a world of difference for the durability of the finish. Any normal primer can be used for wood or fiberglass. (I usually thin it out alot to allow for good penetration of surface)

BEWARE!!!: Multi-stage paint/Urethane clearcoat requires hardener which will most likely contain cyanide. (NASTY!!) A great finish is not worth dieing for!! Make sure you use a proper respirator (Particulate filter is not enough!!) and ventilate your paint area well!! (BRUSHLESS exhaust fan!...or KABOOM!!) :-[

Also wear eye protection!!! This stuff will turn your eyes to jelly. (ICK!)(Again...your finish is not worth going blind over!!)

Epoxy paint is a little less toxic when being applied...but you should still protect your health!!

I hope this helps.

 

[TimD]

Sheeeesh,

Remind me again why we are still using wood??? Composites and Gelcoated 'glass is looking better all the time!

Seriously good post Jeff K. Thanks for sharing your knowledge on this subject - especially the safety issues.

Tim.

 

[Jimboat]

I agree with Jerry Dunlap with respect to using the West System Epoxy. Although good epoxy is expensive, I have found West System to be about the best, and it's not much different in price than other similar epoxies.

A few light coats will work best, sanded between coatings. For fileting and fixing cracks, West also makes a good filler that just mixes with the base epoxy. Works great.

Should sand runing surfaces with 400-600 grit AFTER final coat has dried well.

 

[Don Templeton]

Just go to your local bump shop and have them paint it.

It is easy.

Thanks,

Mark

Tried that shoboat, they wanted 175.00 for a .12 rigger/1 color

 

[TomMoorehouse]

hey JeffK I have the PPG omni AU clear. Your saying I could spray that over redular spray can paint and it will fork fine?

 

[Propjockey]

Don, give this a shot.

I slipped a guy at the body shop a $20 and told him, "Next time you spray some red, suppose you could clean your gun out on this?"

Had to leave it with him for a week or so, but..............

BTW--make sure it's completely prepped (sanded, masked, etc.) so he doesn't have to do anything but paint it.

The guy said the more he looked at it, the more he got interested and when he got around to painting it, he did a really nice job.

 

[Don Templeton]

I tried that Propjockey. It didn't work.

Guess I need to find a different bump shop. :

 

[jklimpel]

Tom;

What kind of hardner does it use?? Does it contain reducer or some other thinner??

Straight hardener usually requires 4-1 (UC-hardener). Thinned/reduced hardener is 2-1, or 1-1.

You can spray UC on almost anything, but you have to make sure you don't use too much thinner which may 'lift' your paint.

If its just hardener (no thinner)...it will work great. You will have to .400 sand your model 1st. The paint will appear dull. Don't worry. It will look fine once the UC is on.

If your finish is already chemically resistant before spraying the clear, using reducer or a thinned hardener is fine.