Lessons learned

[gdest]

I thought I would start this thread that would help others avoid some time consuming and frustrating operations during their oven build and plans.

What I would like to do with the lessons learned is not only state the lesson but explain why you should avoid it. This will help hard headed people like me who usally ignore suggestions unless the rerasons to avoid them are given.

I will be updating this as I continue with my build and hopefully others on this forum will add to this so that I may be able to avoid some of the pitfalls I am sure to encounter as I continue.

Here is lessons learned #1

1. Do not use white portland cement when mixing with perlite or vermiculite.
Reason: You cannot tell if you have thoroughly mixed the concrete with the perlite since both are white. Not having a proper mix will create "soft" spots in your perlite concrete.

[Tscarborough]

Re: Lessons learned

To say nothing of the fact that it is twice as expensive as gray.

[fxpose]

Re: Lessons learned

These are my views on cutting brick:

Spend a few extra bucks and get an inexpensive segmented diamond blade for your miter saw or grinder. (Amazon sells them real cheap. I bought a 10" blade and two 4.5" blades for about $50, no tax, free shipping)
I thought I would save money by using cheap abrasive blades but they take waaaay too long to cut and wear down quickly. Compared to these, the dry cutting segmented blades cut through brick like butter. Just make sure to soak your bricks in water throughly for a couple of hours before cutting. The blade will last longer.

Also, if you have an old miter or cut-off saw, get a segmented diamond blade for that instead of purchasing a dedicated wet brick saw. A little messy, but they work just as good.

George

[Billz]

Re: Lessons learned

"Just make sure to soak your bricks in water throughly for a couple of hours before cutting"

If you did this wouldn't you have to let them almost dry out before you set them. I thought I read here somewhere that if you over wet the bricks you would weaken the bond when setting?

[gdest]

Re: Lessons learned

I thought I should add this one even though it SHOULD BE a no brainer.

When mixing the perlite and portland cement WEAR A RESPERATOR! In fact you should wear a resperator whenever you are mixing or working with concrete. Now to explain:

1. Perlite is very light and will go everywhere. You will inhale this and start choking.

2. As for the concrete, concrete dust contains crystalline silica can lead to a disabling lung disease called silicosis.

3. In addition to the silica concrete dust contains small amounts of Hexavalent Chrome. OSHA lowered the limit about 4 years ago to the allowable exposure limits. What is Hex Chrome you may ask? Remember the movie Erin Brockovich? Same stuff.

[Tscarborough]

Re: Lessons learned

When you say small amounts, you are talking REALLY small amounts. For example, the free silica is from Zero to less than 0.1%. Other elements, like the Hexa-chromium, are trace. The worst damage from Portland cement will be from alkalinity burns.

You should always wear gloves and a dust mask, no respirator needed.

Here is a sample Portland Cement MSDS:

HOME

[gdest]

Re: Lessons learned

Tscarborough

You are correct, I looked up the OSHA Std for CrVI and it does specificly exclude portland cement. However just for me to save face when I use the term respirator I really meant dust mask.

[Tscarborough]

Re: Lessons learned

No worries, this is just my area of experience, so I contribute where I can.

[david s]

Re: Lessons learned

Although perlite is a marginally better insulator than vermiculite, that is its density is slightly lower, it creates annoying dust, which vermiculite does not and it breaks down more easily when mixing, resulting in a slightly reduced volume. I prefer to use vermiculite rather than perlite every time. It's cheaper too.

[gdest]

Re: Lessons learned

Ok some of MY lessons learned may be no brainers for most of you but here goes some more.

1. If you are using the HF wet saw, let the saw "float" do not lock it in with the locking knob, unless you really need to hold a specific height. By letting it float the saw blade will not jamb so much as a result of trying to push the brick in to fast.

2. If you are like me and could not get any fire clay, just go ahead and cut your 1st course you should have enough fire clay to mix with your sand to use as leveling for your floor.

[gdest]

Re: Lessons learned

"Just make sure to soak your bricks in water throughly for a couple of hours before cutting"

If you did this wouldn't you have to let them almost dry out before you set them. I thought I read here somewhere that if you over wet the bricks you would weaken the bond when setting?

No you will not weaken the bond, in fact from what all of the instructions I have seen warns you to soak the brick to keep drawing out the moisture from the fire brick to much thus weakening the bond.

[Raffy]

Re: Lessons learned

Gosh, where do I start? Building an oven teaches you a lot of stuff but before I start getting philosophical, let me begin my list with:

1. PROPER SAFETY WHILE HANDLING CONCRETE. ALWAYS WEAR PROTECTION (i.e. latex gloves)

My hands have never returned to normal since handling concrete without any protection. Now, everytime I shower or even when I just wash my hands, they immediately turn pruny even if its just for a moment. I'm assuming it is a result of alkaline (caustic) skin burns to my hands due to handling concrete unprotected. You never notice any effects to your skin but definitely there is damage being done microscopically. PH level of concrete is roughly 12 to 13. Even when I realized early on to wear latex gloves, the damage had been done but hopefully its not permanent. Someone taught me to rinse my hands in a mixture of vinegar diluted in water to wash off any cement.

I'll edit this reply as I remember other important lessons I've learned while building my oven.

[gdest]

Re: Lessons learned

Ok some more leasons learned here.

1. Someone else mentioned this somewhere else, but I will also bring it up here. If you are using the HF wet saw, put the pump in a 5 gal bucket. This will help the pump from sucking up the brick clay that you get, AND YOU GET ALOT!.

[gdest]

Re: Lessons learned

Major leason learned here. Watch out if you get too much help with the oven. This is the result!

[david s]

Re: Lessons learned

Make sure you use a dust mask, preferably a respirator when cutting bricks. Inhaling the dust from fired bricks is dangerous.