Reducer

[LENZ]

I have been painting with Awlgrip (roll ant tipping) and when reading the mixing instruction it says "add 5% to 30%" of reducer to the paint mixture, so my question is: what does more reducer do to the paint as oppose to less? does it dry faster with more, or flow better with less? All in all I having pretty good results so far, I just want to understand what I'm doing, if that make any sense?..

Thanks
LENZ

 

[dastahl]

Reducer is a thinner. Reducers make the paint less viscous so several things happen. The film thickness is reduced, the paint will break up better thru a spray gun, and it will flow more. It rarely effects drying but will keep the film wetter longer. It increases the tendency of the paint to sag. Rolling and tipping generally used less reduceer and a different reducer than spraying.

If you want more flow while tipping add very small amounts of reducer until you find what you want. Make sure you use Awlgrip reducer for rolling and tipping. Most paint companies make reducers for spray or brush, you would use the brush.

You will find that the paint acts differently on different days. This is due to temp/humidity. Painters add less or more solvents to get what they want. Its an art.

Have fun.

Skooch

 

[LENZ]

Reducer is a thinner. Reducers make the paint less viscous so several things happen. The film thickness is reduced, the paint will break up better thru a spray gun, and it will flow more. It rarely effects drying but will keep the film wetter longer. It increases the tendency of the paint to sag. Rolling and tipping generally used less reduceer and a different reducer than spraying.

If you want more flow while tipping add very small amounts of reducer until you find what you want. Make sure you use Awlgrip reducer for rolling and tipping. Most paint companies make reducers for spray or brush, you would use the brush.

You will find that the paint acts differently on different days. This is due to temp/humidity. Painters add less or more solvents to get what they want. Its an art.

Have fun.

Skooch

Thanks!! It all makes sense to me now!!

Lenz

 

[Brian Degulis]

More reducer makes a thinner film the solvents will evaporate quicker so the paint will dry and cure faster. Typicaly you adjust the paint with the reducer depending on the temp wind and the complexity of the surface your painting. You want to add enough reducer for the paint to remain wet and managable long enough to get it on the surface and smooth it out. You can blend spraying and brushing reducer. If the temp was down and the wind calm adding some spraying reducer will speed up the set up time preventing runs. If it's hot and breezy brushing reducer will slow the set up time so you can smooth it out. The right mix makes all the diffrence.

Brian

 

[TedZ]

Wow!

The awlgrip application guide is the best answer for these questions. Very generally without trying to impune any particular answer...

Thinners come in different drying times designed to effect drying! No surprise. Fast thinners for when the air temperature is cool, "sweet" thinners when it is warm or you are brushing or tipping and rolling. The amount you add can vary but it is done for application effect as opposed to controlling drying. Depending on your equipment, less thinning is better as coverage is better but you want the paint to flow out, i.e. be smooth without sags. When that is the case for your equipment and climatic conditions and the temperature of the surface to be painted, the amount of thinner is then optimum.

Catalysts need to be added in very strict accordance to the manufacturers reccommendations. A few percent off is a LOT with some paint formulations.

With two component paints i still like Zahns cups for measuring viscosity. It saves a lot of hastle when you are using different thinners or blends of them, and if your paint is too hot or cold.

When you are spraying, one of the things that i believe is necessary is to call the paint rep (not the store) and ask what the hot setup is for the paint you are using. They will tell you if you are using xyz equipment, model abc we have guys using the xxx fluid tip and the yyy air cap. Painting a boat is a big deal. Once you decide on the paint it is best to buy the equipment the rep suggests. $300 is chump change to what you are saving DIY so buy it!

My $.02 not intended to offend anyone.

Ted

 

[MikeP]

Remember that adding thinner reduces the amount of paint you are laying down. This can be a problem because paint needs to be a specified thickness to perform well. SO when you spray, and the manufacturer calls for (as an example) 3 wet coats, you need to also determine what the thinning will do for that.

As an example, if you thin 30%, then spray 3 wet coats, your mil depth is NOT going to be what you think it is because 30% of every coat you sprayed wasn't paint.

Obviously, this is much easier if the manufacturer says to thin X amount and then spray x coats. That way, they have already figured it out. The best way is, as Ted mentioned, the viscosity cup. Most paints will state what the viscosity should be. Otherwise, you are just shooting in the dark I have seen paint jobs where the paint was thinned 50% (with no attention to viscosity if specified) to get a good spray but no additional coats were added and the paint layer was too thin and failed quickly.

I would think this is pretty unlikely with a rolled/brushed coat. In fact, I would expect the opposite problem to be more likely - paint that is too thick and would tend to crack/check for that reason. But I have never rolled/brushed any paint that is considered a finish paint for on/offroad vehicles so I have no experience at all with that method of application.

 

[Brian Degulis]

As an example, if you thin 30%, then spray 3 wet coats, your mil depth is NOT going to be what you think it is because 30% of every coat you sprayed wasn't paint.

Awlgrip and Imron are thinned a lot more than commercial paints to get good atomization. When you thin a lot two things happen a lot of the thinner flashs off before the paint hits the surface. Then a lot of the paint blows back off the surface into the air. So you end up with a very poor transfer rate and use a lot more paint. So to get the 3 wet coats you refer to above will require spraying a lot more mixed material but the actual mill thickness will change very little as a result of thinning. This assumes that your working within normal parameters for a high quality finish. I have done commercial jobs with awlgrip without thinning at all. When you go to that extreme yes you do get a heavier film build per coat.

Brian