A friend of mine is rebuilding his fence (ok, it’s a bit different) with concrete posts. They are not very intricate, but have some detail to make them pretty, and not just rectangular blocks. The question is: what is the best substance to let the forms release from the concrete, probably a few days after the pour (which is Friday)? He made the forms out of MDF, and will do some sort of acid (myriatic acid, maybe- I can’t spell chemicals, forgive me) once he pulls the forms. He has been recommended some commercial form release, and also a mix of diesel and motor oil. What is the best solution for this? Thanks, as always.
Young, poor, and eager to learn
Replies
I'm not a concrete guy at all - but don't they make a form oil for that application? Spray it on with a hudson sprayer type of thing.
"...never charged nothing for his preaching, and it was worth it, too" - Mark Twain
yes they do make a form release agent...someone already has recommended it to his freind
"He has been recommended some commercial form release, and also a mix of diesel and motor oil. What is the best solution for this? "
I think he is asking what is better.
MDF for form work? I'd use MDO ( medium density overlay) also known as paper faced plywoood.
as for your question; he already has a recommendation, so you are wanting to know which is better the release agent or the concoction?
I've done a fair bit of formwork.and most times a release agent is used. I've also used straight diesel fuel, (rarely) but not a mix. ( doesnt' mean you can't, I just havn't heard of it)
I doubt that diesel is ever used because it works better, only because it may have been cheaper or more readily available.
Edited 8/23/2006 2:20 am ET by alrightythen
http://www.symons.com/products/brochure/chemical/01fr.htm
symons is the biggest name around in forms and you should be able to get this from a local dealer.
i haven't worked with MDF that much, but i'm pretty sure it doesn't like anything that is wet.
like form release agent, concrete or rain. usually results in major swelling.
carpenter in transition
problem with diesel as a release agent is the odor after you pull and the EPA people will put you under the jail,
They dont get down to Arkansas much.
Weve always used deisel and used motor oil. Old boat gas and a lot of oil does it too. Reminds me of airing up tires with propane .
Tim
seal the heck out of the mdf with polyurathane, then mold release. try polytek.com
The guys here who make biodiesel also make a form release agent that is non toxic, biodegradable, cheap, and supposedly works better.
How much is that gonna cost me ? <G>
Tim
More than the undiluted used motor oil I use. First use of the plywood forms is to the dirt side. Vast majority of my used motor oil is diesel (black).
Works very well.PAHS Designer/Builder- Bury it!
Have done very little concrete work but a couple weeks ago pulled the forms off a concrete pier that I built alongside the waterfront of the cottage. I realized right before pouring that I might need a release agent...so only thing I could think of that I had on hand was PAM cooking spray! Worked like a charm.
if he's going to acid stain the concrete after he pulls the forms... any petrol product is going to screw up his staining, as will most wax based release agents...
PAM does work well... used it on some concrete sink forms... actually used the very cheap BIG LOTS stuff vs name brand....
I don't know what color he's after but... any of the powder mortar colors mixed in his mix have worked well for me.... (not the colored mortar the color that goes into the mortar)
automotive paste wax on his forms will go a long way...
i can get an almost mirror finish on my cast concrete when i use lexan for the form or line the form with it... i get old lexan sign faces for free from the sign guy ...use the backside...
formica also works really well and you can get alot of textures with it...
good luck & take some pics
p
My form rental Co uses vegetable oil, presumably canola. And it works well w/out all the smell and contamination.
All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
Well, just finished the pour a couple hours ago. He wound up finding some commercial form release, and used that. I'll try to swing by in a few days after he pulls the forms to see how it looks. Thanks for all the advice, as always
Young, poor, and eager to learn