Hardener

[Site Man]

OLD FORUM POSTS

Posted by Joe Crumley on October 27, 2002

I have been using (with concern and caution) the hardener from Mathews Paint Co. as an additive to my Ronan and One Shot enamels. This gives a glossier and harder surface. I am told this will cut down on the chalking also.

Have any of yoose tried it?

I've also been using Mathew Clear on my permanent signs for years. It covers vinyl letters beautifully. I have never had a failure. I highly recommend it not only for protection, but the also for the hot dang good looks.

Joe

Harry Spetnagel

Joe- I'll start by saying that I am no chemist. However we have used tiny amounts of the Matthews Hardner/Catalyst in enamels (3 drops per half pint) with good success. This however is only done when brushing enamel on top of a Matthews MAP Painted background. It seems to help the adhesion of the enamel to the background and I hear it will help keep the enamel from lifting when clearcoating although we don't clearcoat much of anything for exterior use at our shop. The UV in Colorado tends to blow up clear coats in short order. I will tell you however that Matthews MAP does not go over enamel period. Instant cottage cheese. At least that has been my experience. Kent Smith is probably a good source of information with regard to the actual chemistry involved.

Good Luck.

Kent Smith

Look also at my answer below under clears. While it may seem that adding Matthews hardener works in the alkyds as it will give it a fast top set, it does not allow the resin to cross link. I would suggest getting the enamel hardener which One Shot has and which we know is compatable with the alkyd enamels. As to adhesion, certainly adding a hardener will improve the quality of the paint fild but it will NEVER aid adhesion. The thought which I hear a lot that adding the reducer for the basse paint will aid in adhesion is also bogus. With only some exceptions (ie wet on wet etc.), adhesion is more a matter of physical bonding than it is chemical. If the substrate has good tooth, no matter what its properties are, adhesion will be good to the limit of the resin of the top coat in the first place. Adding a hardener to aid in producing a tougher paint film is the only chemical advantage you can produce.

Joe Crumley

Thanks for the back-up information on hardners. I tried adding a hardner to geta better finish. We have not tested for proportion of but it doesn't seem to be too critical.

I have been stunned by the quality of the Mathews MAP clear. This is a good solution for folks at high altitude like Colorado.

Haven't tested MAP over One Shot backgrounds. Probably wouldn't work, but you can spray it over aluminum coated boards which have been lettered with vinyl. I scotchbrite both lettering and background and spray away. Two fat coats should dry to touch in a hour or two.

I just complete a series of antique signs for "Medicine Park", which were painted with wather based exterior anamels. The Mathews clear did not lift the paint. I went pretty light with a couple of clear coats.

Thanks again.

Joe