Anyone have experience tearing out epoxy? Mainly it’s between some pieces of wood I’d like to tear out, attaching them to some nearby surfaces.
Would a heat gun melt it away?
Would a sawzall cut through it, mebbe with a carbide blade? I’ve used a sawzall to cut CI, not fun but doable….
Would an angle grinder be able to trim away pieces that are left?
Can’t find out by experimentation, if I start this there is no turning back….
Oh there’s a plaster ceiling underneath, one of the attached surfaces, so jack hammers are out….
Replies
Most epoxies are pretty tough stuff when cured. I doubt very much heat or solvents are going to get you anywhere. A lot of them are pretty brittle if chipping is an option, otherwise I imagine you're going to be cutting or gouging it out.
Actually epoxy is fairly heat sensitive.
I have used heat many times to break epoxy connections, but they where in metal. Don't know if you can get it hot enough with a heat gun or not.
But it is also fairly brittle. You should not have any problem with a recip saw with a standard wood/metal demo blade.
I hear it goes soft at 140* F, just a little nervous about igniting the old wood at that temperature, and it'd probably harden up again before I could do anything with it.... Thanks for the recommendation on sawzall.... I've also wondered about freezing it to make it very brittle, but it can handle temperatures down to 0* F....
140 is not that hot with wood. Otherwise you would see a lot of attic self combusting.However, you will have to get it hotter to get the joint hot.If you had a hot air gun I don't think that you could do any damage before your arm got too tired to hold it.How if you where using a torch that would be different matter.I have forgotten, but I think that it is not until 250-350 that wood starts giving up volitale compounds.
Edited 4/21/2005 10:27 am ET by Bill Hartmann
Wood will not ignite until 450F or so.
Epoxy has high tensile and shear strength, but is not particularly hard, so it cuts easily enough.
Paper ignites at 451F. Wood ???The sawzall will do the job. See if you can find a backwards universal cut blade. Pulling the epoxy chips/slivers/whatever toward you is best. Clears the cut as you go.
A person with no sense of humor about themselves, has no sense at all.
I was thinking that wood ,Pine , would ignite at 1200 degree . I tthink that was what the welding instructor told us . He used a wood match stick to test the temp of metal . Don't recall the reason he needed to check the temp but do recall the wood igniting.
Your welding instructor was wrong.
When I worked in old growth sawmills, we used steam for everything from shotgun driven log carriages to dry kilns.
Occasionally, the powerhouse boilers would send, instead of the required low-pressure, 350 to 380 degree steam, a burst of the 450 degree stuff they were sending to the pulp mill.
Result was ignition of wood debris in direct contact with steam pipes.
It was a while ago so I may have remembered it wrong.
The saw is probably the most practical/certain approach. Problem is that epoxies vary considerably in their hardness -- some are darn near gummy -- and the SOFT stuff is what may give you the most trouble, by creating intolerable blade drag and just chewing up vs cutting cleanly.
An angle grinder could manage the harder stuff (especially most filled epoxies), but wouldn't do too well on softer stuff.
Best bet is a recip saw with coarse teeth. You want to cut big chips out and pull them away before friction can heat the material and turn it gummy. Fine teeth would be worse, and an angle grinder even worse than that. You need to advance the saw fairly aggressively. Consider running a shop vac while cutting to get chips outta there, and keep cool air flowing.
-- J.S.
I just finished up a long bar for a brewery that is getting ready to open soon. I used epoxy over an old, rough sawn beam that we pulled out of the lake. Over the coarse of the project I had to remove a lot of the material when it went into the wrong places. Grinders work great with a 36 gt sanding disc in them if the epoxy was mixed and cured correctly. Sawsall blades and even skillsaw blades will work, but the skillsaw tends to break the epoxy up and send little shards flying, so be very cautious with high speed saws. Hope this helps!
Epoxy is quite toxic when burned, so heating it too much is a really bad idea. Softening it with a little heat might be safe. But I'd think it would cut fine with a bimetal blade.
Thanks all for the suggestions, and the toxicity warning.