When filling holes and cracks in plaster, does the depth of the damage determine the product used to repair? For example, If the plaster is missing from the lath you'd need to start with basecoat and then finish with a topcoat, correct? Is a two layer process acceptable, or do you need scratch,brown, finish? For filling nail/ screw hole damage, is drywall compound/ spackling acceptable? I'm trying to educated myself on drywall finishing as well. I've watched guys use setting type compounds, fiber reinforced compounds, finish coats that are easy to sand. Lots of reasons and opinions out there.
Can anyone give me a run down on the products generally used and whether they are acceptable/interchangeable for both drywall and plaster. For instance, I've heard of a fiber reinforced product called Confil. Would this modern product be a substitute for basecoat? Is regular all purpose joint compound an acceptable top coat for plaster? I'm trying to understand where past and present meet with acceptable results. It may help me decide between repair or removal.
Thanks for any help.
For filling areas where the lath is exposed you should use a base coat material. In these areas you should clean the space between the laths, Than on the edges where the existing Plaster is to remain back cut the edges of the plaster (back cutting is cutting an angle @ say a 45* under cut so the new base plaster is under the existing finish)
The best material for this repair is a Perlite Plaster using this you only need to add water & can mix only what is need @ the time. Before the repair is started using a spray bottle mist the repair area down with water, or better use 1/2 water & 1/2 bonding agent like weldcrete or equal. One coat of base is fine. Leave the base coat back 1/8" or match the existing finish depth. For the finish use a Plaster product like USG Diamond Finish Plaster or equal. Also pre wet before applying the Finish. As for small nail holes use just the Finish Plaster.
When using mesh tape with a Plaster product I would recommend that you use mesh that is designed for the product selected example USG Diamond Finish use USG Imperial Brand Tape.
As for the use of a Joint Compound applied over Plaster in my 41 years of doing Plaster repairs I would NOT recommend it, it will fail & moisture will be your big problem that causes failure when it is used.
A setting would be the most compatible but I would only use it as a last result. If your existing Plaster is stable & NO other repairs are needed or will be included look at these products.
Plaster Magic = to reattach Plaster to the Lath.
A Veneer Restoration Plaster = example Master of Plaster or Equal.
The use of a Plaster product requires no sanding.
Do not let the Cost of the plaster products scare you off.
Call Lauren @ Master of Plaster @ ask her if you can get a wet sample to try on your existing plaster The number is 803-403-5252 tell her Hank told you to call I have NO connection I help get her started in her business.
