Sign up Latest Topics
 
 
 


Reply
  Author   Comment  
BadBob

Avatar / Picture

Registered:
Posts: 1,618
Reply with quote  #1 
I painted two dinosaurs with latex paint. One with Gliddenand the other with Behr, The first coat cured ok and I sanded them and applied a second coat. That was two days ago and they still feel sticky to the touch. I can scrape the paint off with my finger nail. Has anyone here had this problem.

I have two cars painted with Behr oops paint from Home Depot ant they didn't have this problem.

__________________
Advanced techniques are the basics perfectly applied.
Odin's Toy Factory Etsy Store
Facebook
Pinterest
Blogger
Forum Photo Album

LinkedIn
YouTube
Google Photos Toys Album

john lewman

Avatar / Picture

Owner, ToymakingPlans.com
Registered:
Posts: 2,819
Reply with quote  #2 
Thanks for posting. I have also had this problem at times. I am not sure if it was old paintor contaminated paint. It is most likely the condition of the paint before it was applied. I have used oops Behrs with no problem. It is non-toxic and washable and makes a durable toy finish.
BadBob

Avatar / Picture

Registered:
Posts: 1,618
Reply with quote  #3 
I picked up the Behrs at Home Depot less than a week ago and the Glidden from WalMart on the same day. I don't think they are old and the first coat was fine. I don't think its likely that three different cans of paint from two locations would have the same issue. I'm betting it is a humidity issue. Right now the outside humidity is 89%. Yesterday at this time it was 100% and didn't get below 80% until late after noon. Indoors the humidity is hovering around 50%.

I'm thinking about baking them in the oven on warm and see what happens. I had some polyurethane that would not cure on car bodies cut from a particular piece of wood. Baking worked fine for these but it took two days.


__________________
Advanced techniques are the basics perfectly applied.
Odin's Toy Factory Etsy Store
Facebook
Pinterest
Blogger
Forum Photo Album

LinkedIn
YouTube
Google Photos Toys Album

john lewman

Avatar / Picture

Owner, ToymakingPlans.com
Registered:
Posts: 2,819
Reply with quote  #4 
Wow! That is high humidity. I had a little wood toy factory in the 1970's where the humidity was this high in the shop all the time. I had the same problem. I ended up making a humidity tent. I used a bunch of 2 x 2's and a couple of rolls of contractor's clear vinyl drop cloths to make an 8' x 8' x 6' high cubicle of a tent. It was wrapped on sides top and front. I used a staple gun to attach the plastic sheeting to the 2 x 2's. The front was a flap of plastic that held shut with a couple of pieces of duct tape.

I used a $99 humidifier from Home Depot to dry out the air inside. It would get bone dry in about 30 minutes. And with humidity in the high teen's and low 20's in the tent the drying time for the paint was unbelievably low. A smaller version could be built for about any shop. I attached a garden hose to the humidifier drain port and directed it into a plastic pan that Home Depot stocks for water heaters. It worked perfectly to collect the water and was easy to empty.
BadBob

Avatar / Picture

Registered:
Posts: 1,618
Reply with quote  #5 
Putting them in the oven on warm cured the paint enough that I could sand it. However, I was not happy with the results. The paint was still soft and had a tendency to come off in little rolls that stuck to every thing. I don't think I will be using latex paint for toys again.

Right now, the humidity is 96% at 0500 eastern time under clear to partly cloudy skies. The lowest predicted for today is 76%. It's like this all the time. The dew is so heavy that it looks like it rained over night. My tools are in my garage and I will not open the garage doors in the morning unless I have too.

__________________
Advanced techniques are the basics perfectly applied.
Odin's Toy Factory Etsy Store
Facebook
Pinterest
Blogger
Forum Photo Album

LinkedIn
YouTube
Google Photos Toys Album

ctowne

Avatar / Picture

Registered:
Posts: 1,054
Reply with quote  #6 
BB - I just had to look up where to live to see where that humidity is.  I've not experienced this problem.  Sorry. 
BadBob

Avatar / Picture

Registered:
Posts: 1,618
Reply with quote  #7 
I did a little research on latex paint and humidity. It was a bit difficult because most of the companies don't give you numbers. The like to use terms like excessive and high which don't really tell you much. Eventually I came up with this.

Humidity needs to be around 50%.  If relative humidity is over 70%, it is risky to paint. At the humidity levels I am dealing with latex paint will reabsorb moisture from the air preventing it from curing properly.

Temperatures below 50 degrees or above 90 can also be a problem. 70 degrees is ideal.

Curing time for latex pain is 3 to 4 weeks. This long because it cures from the outside in and can reabsorb moisture from the air. Dry means that if you touch it you will not get paint on your fingers. Cured is dry all the way through. Interestingly, oil based paint takes 4 to 10 hours to dry and and cures in 3 to 4 days. Oil based paint cure from the inside out.

Outside of installing a dehumidifier or painting inside the house there isn't much I can do about it.

__________________
Advanced techniques are the basics perfectly applied.
Odin's Toy Factory Etsy Store
Facebook
Pinterest
Blogger
Forum Photo Album

LinkedIn
YouTube
Google Photos Toys Album

ctowne

Avatar / Picture

Registered:
Posts: 1,054
Reply with quote  #8 
I have had this problem once or twice and it has been extremely hot and humid.  I don't live too far from you but my humidity and temps do not stay consistently high.  it does look like John's painting tent is the option. 
BadBob

Avatar / Picture

Registered:
Posts: 1,618
Reply with quote  #9 
Acrylics seem to work well for me and dry fast. When I compare costs the acrylics are not more expensive than the latex even in the little 2 oz bottles. So no tent for me.


I tried the latex because I am experimenting with finishes and the oops paint in the sample cans a Home Depot is only fifty cents. This is much cheaper than acrylics.

I may just go back to bare wood and polyurethane. 

__________________
Advanced techniques are the basics perfectly applied.
Odin's Toy Factory Etsy Store
Facebook
Pinterest
Blogger
Forum Photo Album

LinkedIn
YouTube
Google Photos Toys Album

ctowne

Avatar / Picture

Registered:
Posts: 1,054
Reply with quote  #10 
bare wood is my favorite but when it boils down to a kids choice, it seems to always be color.  I have not tried acylics, good to know.  Good luck, this painting thing has been the most difficult part of making toys for me anyway, lots of experimenting.....
BadBob

Avatar / Picture

Registered:
Posts: 1,618
Reply with quote  #11 
I did some painting with several colors and brands of acrylic craft paints today. By the time I finished to first coat on the last piece the first one was ready to sand and apply the next coat. Three coats of paint back to back.

A simple toy. My grandson loved it.

__________________
Advanced techniques are the basics perfectly applied.
Odin's Toy Factory Etsy Store
Facebook
Pinterest
Blogger
Forum Photo Album

LinkedIn
YouTube
Google Photos Toys Album

Indy82

Registered:
Posts: 10
Reply with quote  #12 
John

I am sure it was a typo but I am almost positive you used a de-humidifier.  A humidifier would add water to the air.
BadBob

Avatar / Picture

Registered:
Posts: 1,618
Reply with quote  #13 
I've come up with a solution that I think will work. I've put a hygrometer in my garage and will not use latex paint unless the conditions. are near perfect. It 61% and 68 degrees in the garage this morning.  Out side its 93% and 61 degrees.

Acrylics seem to work fine at higher humidity but the oops paint from home depot is fifty cents and I have managed to score lots of colors. Even if I need to get some mixed the color selection is much better than I can get locally for acrylics.


__________________
Advanced techniques are the basics perfectly applied.
Odin's Toy Factory Etsy Store
Facebook
Pinterest
Blogger
Forum Photo Album

LinkedIn
YouTube
Google Photos Toys Album

Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.