Pottery Magic Home   Weekly Letter Mail List

Pottery Magic Small Goblets

Pottery and Ceramics Tools

Common Kiln Firing Faults


Bubbled glaze, craters or pinholes could be caused by:

Follow My 40 Day Pottery Challenge

Becca's Montana Girl Blog

Pottery Videos

Pottery and Ceramic Tools

Tools for Pottery

Pottery Magic Wand

Tips & Techniques
for Pottery and Ceramics

Pottery and Ceramic Projects

Clay Pottery Craft Projects

Pottery Magic Wand

Clay Pottery
Articles of Interest

Pottery and Ceramic History

Old Time Pottery History

Pottery Magic Wand

Pottery and Ceramics

Featured Potters Gallery

Pottery and Ceramics Definitions

Pottery and Ceramics

Pottery Magic Wand

All About The Clay

Glazes and Decorating Pottery

All About Pottery Glazes

How a Pit Kiln Works
Digital Kilns, How They Work
How To Pick A Kiln For My Needs
More Info On Picking Out A Kiln
Different Types Of Kilns
Tips for Complete Kiln Care
Monthly Kiln Maintenance
Kiln Safety
The Magical Kiln God
Do I Need A Kiln Vent?
Kiln Sitter
Troubleshooting Your Kiln Sitter
Kiln Firing Gauge
Roman Kilns
Kiln Patching
Kiln Wash
TeePee Kiln Firing
Cooling Rate of Kiln
Coat per Kiln Load
Building a Fast Firing Kiln
Placing, Checking a Witness Cones
How Different Temperatures Effect Clay
Electrical Plugins
Carbon Burnout Problems And Solutions
Cracks In Bottom Of The Kiln
Kiln Temperature Distribution
What Is Your Kiln Trying To Tell You
Pyrometric Cones Q&A
Pyrometric Cone Firing Chart
Common Kiln Firing Faults
What About Kiln Elements
Making Fire Bricks Last
Kiln Furniture
Loading The Kiln
Vegetable Oil Firing
Temperature & Rate Conversion Formula
Kiln Firing Logbook

Underfired or immature bisque.

Most often the bisque is fired to a cone 03 or 04.
The glaze firing is generally fired 1 or 2 cones cooler, 05 or 06.
If the bisque has not been fired completely through, gases will escape from the immature bisque causing small pinholes, craters or bubbles in the glazed surface. Read all directions on the color manufacturers products for correct firing temperatures.
Get a hold of your slip or color manufacturer should you have questions.

Glaze could be applied to heavy.

Apply only the number of coats according to the color manufacturers directions and label.

Dust on the ware or in the kiln.

The ware should be free from dust by brushing the dust off with a soft brush or a damp sponge.
Vacuum your kiln, including inside the grooves, to keep it free from unnecessary dust.

Firing too fast or cooling too rapidly.

With the no-lead glazes, rushing through either of these processes will bring these unsatisfactory results.


Paint has not been fired to maturity which will then rub off.
Paint that is not mixed properly and thoroughly.
Pottery that is dirty or has a film coating the piece.
Clean the piece good with alcohol.
Improper firing procedure.


Crazing is recognized by many hairline cracks on the glazed surface after the ware has been fired.
This will not necessarily occur immediately after the final firing but over a period of time the hairline cracks will become visible.

Crazing and cracking could be caused by:

Bisque or greenware that has not been thoroughly fired. Greenware must be completely dry before doing a bisque firing.
The piece should be fired to a cone 03 or 04 making sure the pieces are not crowded and adequate heat circulation surrounds all the pieces.
If the pieces are not thoroughly fired, moisture will be trapped inside the ware.
This will cause the crazing and cracking to occur during the glaze firing.
The moisture and gases are escaping and disrupt the smooth glaze finish.

Either cooling the kiln too rapidly or removing the ware before it is completely cool. Do not hurry the cooling process or raise the kiln lid before it is cool.
An extreme temperature change could put stress on your ware thus causing crazing.

Handling pottery and ceramics too roughly.
Greenware is very delicate and should be handled carefully.
Putting stess on a particular point could cause a crack that would not appear until after firing.
Cracking of flat pieces could be caused from not enough ventilation surrounding the piece.
Flat pieces should not be placed directly on the kiln bottom or shelf.
They should be raised about 1" from the firing surface by using posts or stilts.
This gives good ventilation around the entire piece and eliminates cracking during the glaze firing.

Inability for your clay and glazes to work together.
Make sure you know what type of clay you are using and follow the paint manufacturers directions.
Contact your slip or color manufacturer should you have questions on this issue.


A dirty surface on the bisque ware caused from dust, including greenware dust, hand lotion and skin oils are the most common causes.
Make sure the bisque is free from dust and sponged to removed any foreign material or oils.

Bisque that has not been dried completely will not accept a good application of paint. Dry the ware completely before attempting to paint.

Underfired or overfired bisque could be a problem.
If the bisque is underfired, refire to the correct cone.
If the piece was to have a stain application, the bisque firing will not be as hot as the glaze firing.
Know your design plans prior to your bisque firing.

If the underglaze if applied to thick, it could pop during firing.
Read the color manufacturers instructions thoroughly prior to application.

Incompatibility could be the problem.
Be sure you know what type of color and clays with which your are working to eliminate any problems.


Problems with reds are not unusual and care should be exercised in firing.
Reds dislike high temperature, but love good paint, heavy paint application and good ventilation.
Some firing faults on red may be caused by:

The glaze may be applied to sparingly.
Unless heavily applied, reds will bleach out into tattletale grays and weary looking whites.
Follow the color manufacturers direction for proper application and firing temperatures.

Firing reds with other glazes that are not chemically compatible with the color red. The color will be distorted.
Check with you color supplier on which colors are compatible.

Overfiring can ruin the red color.
It will turn out grayish and not the bright shiny red.

Inadequate air circulation causing insufficient oxygen may result in black spots in the red glaze when matured.
Good ventilation is a must while firing reds.
Sometimes reds are best fired near the bottom of the kiln where it has a tendency to be a little cooler.


Rippling of glazes is caused by too heavy of an application of glaze.
If you get a piece of pottery like this, it is not correctable but good to remember for future work.


Generally, it is impossible to salvage warped pottery and ceramic and is caused by:

Incorrectly removing ware from the mold.
Ware should not be removed from the mold until it is leather hard and releases easily.
This is extremely important in porcelain casting.
Porcelain has a memory and cannot be reshaped.

Overfiring can cause distortion.

Placing the ware too close to an element could cause one section of the ware to mature prematurely and distort.
Keep the ware approximately 1" away from the kiln side walls and tube assembly, if one is installed, and thermocouple, if one is installed, to insure proper ventilation.

Improper support on stress areas could cause warping.
Large flat pieces should be supported with either stilts or posts.
Porcelain should be supported with prop or silica sand.
It is suggested that firing instructions be taken for firing porcelain.

Never corner something that you know is meaner than you

Tips - Definitions - Clay Projects - Pottery Gallery - Pottery Tools - Glazes - All About Clay

Have you ever come up with a good idea while working with your handmade pottery and thought that you would like to share it with others? You have? Well, why not send it to us and we will add it to the tips page for all to see.

Handmade pottery can be a very gratifying hobby that produces fun and satisfying results. For many people it's an enjoyable release that is created by working an inanimate mound of clay into a beautiful work of art that you made through your artistic abilities.

The best way of starting out is to take a few lessons from Youtube. You will probably waste quite a bit in materials when you first get started. Figuring out how to truly make handmade pottery correctly and shape into what you want it to be can be quite an ordeal. The different tools that a normal shop will have can be fun to try. You will soon see which ones you like to use the most and then when you are ready you will know which ones to buy.

With the help of the internet, you can now purchase most if not all of your ceramic and pottery tools and supplies online. We are located far from any well supplied dealers and yet working with reliable ceramic and pottery suppliers online has allowed us to recieve most of our orders within a timely manner.

When you get all set up, just enjoy the hobby and have fun at it. Some people get pretty serious and start selling their creations at craft fairs and small stores, but others just like to create items for themselves, relatives, and friends. Whichever kind of handmade pottery you desire to endeavor, enjoy the hobby and have fun doing it.

Store Home

DeerLake Store
Outback-Hat from the Deerlake Store
Stash It, Smash It, Crush It,
Tye Dye It, Fly Tye It, Simplify It,
Buy It, the OutBack Hat.

Pottery Magic HomeContact UsAbout
Pottery FAQTerms of Service ~ Terms of Use and Legal Notice
Privacy Policy and Security StatementCopyright/IP Policy
Copyright 2001 - 2017 All rights reserved. DeerLake Designs LLC