Frequently Asked Questions about Putty Application! - CMC/HPMC

CMC/HPMC can be used as a thickener and water-retaining agent in mortars, putties, and gypsum in construction, making the materials easier to apply. Shijiazhuang Cellulose Co., Ltd., as a Chinese cellulose company, can provide you with high-quality construction-grade HPMC and CMC chemical powders.

1. What are the components of putty?

(1) Ordinary putty is mainly made of white powder, with a little starch ether and CMC (hydroxymethyl cellulose). This type of putty has no adhesion and is not water-resistant.

(2) Water-resistant putty paste is mainly composed of high molecular weight organic matter, lime powder, ultrafine filler, and water-retaining agent. This type of putty has good whiteness, high bonding strength, and water resistance. It is a rigid, alkaline product.

(3) Water-resistant putty powder is mainly composed of calcium carbonate, lime powder, cement, Nok redispersible latex powder, and water-retaining agent. This type of product has high bonding strength and water resistance. It is a rigid, alkaline product.

(4) Emulsion-type putty is mainly composed of polymer emulsion, ultrafine filler, and water-retaining agent. This type of putty has excellent water resistance and flexibility and can be used on various substrates, but it is more expensive and is a neutral product.

2. How are putty products classified in the market?

(1) By state: paste putty, powder putty, putty with adhesive filler or cement.

(2) By water resistance: water-resistant putty, non-water-resistant putty (such as 821 putty).

(3) By application: interior wall putty, exterior wall putty.

(4) By function: water-resistant putty, elastic putty, high-elasticity waterproof putty.

3. After applying putty, some areas show yellowing. What could be the cause? How should it be handled?

(1) Applying a second coat of putty before the first coat is dry often results in yellowing.

(2) High wall moisture content, and failure to perform a sealing treatment before applying the putty, can also cause localized yellowing.

(3) If the yellowing is due to applying a second coat before the first coat is dry, a coat of white paint can be applied to cover it. If the yellowing is caused by moisture in the wall and the putty used is not waterproof, it is best to remove and redo the putty, performing a sealing treatment beforehand. Recommended sealing treatment: N3-800 elastic waterproof eco-friendly putty.

4. The wall has been coated with putty twice, about a week apart. However, now when I try to pinch it with my fingernail, it leaves an easy mark, and my hand feels white after touching it. What's wrong?

(1) If non-water-resistant putty was used, and no glue or interface agent was added during application, this is not surprising.

(2) If water-resistant putty was used, then there is a quality problem. For example, the putty may have a low glue content, or the white cement, lime, or other cementing materials used in the putty may be of poor quality.

(3) If the putty was mixed on-site, using 108 glue directly mixed with talcum powder and heavy calcium carbonate powder without adding appropriate amounts of cement, lime, gypsum, or other inorganic cementing materials, the resulting putty will have low strength.

(4) To make it easier to apply, the construction workers may have mixed the putty to be softer and with lower strength.