FAQs, Specifications & Warranties

Q1. Why choose DUO-SIL over other caulks?

DUO-SIL is a specially formulated urethane acrylic emulsion adhesive sealant that offers superior performance in a range of uses. The adhesive caulk is available in more than 140 in stock colors and is paintable for enhanced versatility and improved finishes. And DUO-SIL is a low VOC product that is non-hazardous, non-flammable, easy to apply, and easy to clean up.

Q2. How do I choose the right caulk colors?

COLOR CROSS REFERENCE TOOL  

With more than 140 in stock caulk colors, DUO-SIL can help you achieve a truly unique, custom, professional finish. 

DOWNLOAD COLOR GUIDE

Q3. Does the color change from wet to cure?

Yes, like latex paint, the color of DUO-SIL changes from wet to full cure. The color match brochure matches the fully cured shade. For help in selecting the right color for your needs, please view our 140 colors in stock.

Q4. Is DUO-SIL paintable?

Yes, in addition to more than 140 industry colors in stock, DUO-SIL adhesive caulk is paintable with oil or latex paints after curing (48 hours).

Q5. Is DUO-SIL suitable for interior and exterior uses?

Yes, DUO-SIL is formulated for the professional applicator and is suitable for both interior and exterior applications. The low VOC formula keeps odor low.

Q6. What surfaces does DUO-SIL adhere to?

DUO-SIL adhesive caulk provides a superior bond to most common building materials, including wood, metal, concrete, gypsum board, vinyl board, cove base, moldings, foam board, and more.

Q7. What temperature range can I apply DUO-SIL?

You can apply DUO-SIL at temperatures between 40°F and 100°F.

Q8. What is the temperature range for the cured product?

DUO-SIL will perform from 0°F to 170°F.

Q9. Is DUO-SIL mildew resistant?

Yes, DUO-SIL adhesive sealant is mildew resistant.

Q10. Is DUO-SIL a low VOC product?

Yes, DUO-SIL is an environmentally friendly, low VOC product.

Q11. What is the typical cure time for DUO-SIL?

DUO-SIL has a typical cure time of 48 hours. High humidity conditions may cause longer cure time.

Q12. What is the typical shelf life for DUO-SIL?

Unopened shelf life of DUO-SIL is 12 months stored at room temperature.

Q13. Does Bostik offer a warranty on DUO-SIL?

Bostik unconditionally warranties the product for product replacement only. Please see our warranty statement for more information.

Q1. Is using Silicone caulk safe?

Silicone caulk is generally recognized as safe. It should always be used in a well-ventilated area. Other standard safety precautions are listed on the side of each tube of Pure Silicone.

Q2. Is it waterproof?

Yes. Pure Silicone can be used in applications where keeping water out is a necessity. We do not recommend using this product for full submersion applications (swimming pools, whirlpools, etc).

Q3. How do I remove uncured silicone caulk?

Scrape or wipe as much uncured caulk as possible. To remove residual uncured caulk, wipe application area completely with isopropyl alcohol. Be sure that the work area is well ventilated and follow all safety precautions and instructions listed on the product label or as otherwise provided by the manufacturer.

Q4. How do I remove cured silicone caulk?

Using a scraper or razor blade, remove as much cured caulk as possible from the surface. For ceramic tile, marble, etc use 100% mineral spirits and a nonabrasive scouring pad. (Be sure to test for discoloration on a small or hidden area prior to application.) For glass, use a razor blade, removing as much as possible, then apply mineral spirits. Remove excess with a towel or other cloth that will not mark the surface area. For hard plastic or painted surfaces, use rubbing alcohol and soft cloth. Do not use mineral spirits. For porous surfaces like brick or concrete, use a wire brush and mineral spirits to completely clear area of cured caulk. Be sure that the work area is well ventilated and follow all safety precautions and instructions listed on the product label or as otherwise provided by the manufacturer.

Q5. Does Pure Silicone smell?  

All caulk releases some level of odor during its cure cycle, generally within the first 24 hours after the product is applied. Pure Silicone is a neutral cure silicone and does not have the offensive odor of silicone caulk products that are acetoxy cure caulks (Bosti-Sil 25™).

Q6. Do I have to prime before using Pure Silicone? 

No. Pure Silicone can be applied with conventional hand or air powered caulking equipment to primed or unprimed surfaces.

Q7. For Interior use am I limited in use? 

While Pure Silicone and other silicone caulks are formulated for the demands of outdoor environments, they are also suitable for kitchen and bath applications.

Q8. Can I use on both Porous and Non-porous surfaces?

Yes. Pure Silicone can be applied to both porous and non-porous surface areas such as brick, metal and glass.

Q9. Is Pure Silicone Paintable? 

100% silicone products are not paintable. If your project requires painting, we recommend using Duo-Sil Ultra^®, which is paintable, waterproof, and also has the flexibility of traditional silicone caulks.

Q10. What is the typical drying or cure time for silicone caulk? 

A 3/16 bead will normally cure in 24 hours. The cure time may vary depending environmental conditions like high humidity, as this will make the cure process faster. In cooler or dryer conditions, you can expect a cure time of up to 48 hours.

Q1. Is using Silicone caulk safe?

Silicone caulk is generally recognized as safe. It should always be used in a well-ventilated area. Other standard safety precautions are listed on the side of each tube of BOSTI-SIL 25.

Q2. Is it waterproof?

Yes. BOSTI-SIL 25 can be used in applications where keeping water out is a necessity. We do not recommend using this product for full submersion applications (swimming pools, whirlpools, etc).

Q3. How do I remove uncured silicone caulk?

Scrape or wipe as much uncured caulk as possible. To remove residual uncured caulk, wipe application area completely with isopropyl alcohol. Be sure that the work area is well ventilated and follow all safety precautions and instructions listed on the product label or as otherwise provided by the manufacturer.

Q4. How do I remove cured silicone caulk?

Using a scraper or razor blade, remove as much cured caulk as possible from the surface. For ceramic tile, marble, etc use 100% mineral spirits and a nonabrasive scouring pad. (Be sure to test for discoloration on a small or hidden area prior to application.) For glass, use a razor blade, removing as much as possible, then apply mineral spirits. Remove excess with a towel or other cloth that will not mark the surface area. For hard plastic or painted surfaces, use rubbing alcohol and soft cloth. Do not use mineral spirits. For porous surfaces like brick or concrete, use a wire brush and mineral spirits to completely clear area of cured caulk. Be sure that the work area is well ventilated and follow all safety precautions and instructions listed on the product label or as otherwise provided by the manufacturer.

Q5. Does BOSTI-SIL 25 smell?  

All caulk releases some level of odor during its cure cycle, generally within the first 24 hours after the product is applied. BOSTI-SIL 25 is an acetoxy cure caulk and will have some smell associated with the cure of the sealant.

Q6. Do I have to prime before using BOSTI-SIL 25? 

No. BOSTI-SIL 25 can be applied with conventional hand or air powered caulking equipment to primed or unprimed surfaces.

Q7. For Interior use am I limited in use? 

While BOSTI-SIL 25 and other silicone caulks are formulated for the demands of outdoor environments, they are also suitable for kitchen and bath applications.

Q8. Can I use on both Porous and Non-porous surfaces?

Yes. BOSTI-SIL 25 can be applied to both porous and non-porous surface areas such as brick, metal and glass.

Q9. Is BOSTI-SIL 25 Paintable? 

100% silicone products are not paintable. If your project requires painting, we recommend using Duo-Sil Ultra^®, which is paintable, waterproof, and also has the flexibility of traditional silicone caulks.

Q10. What is the typical drying or cure time for silicone caulk? 

A 3/16 bead will normally cure in 24 hours. The cure time may vary depending environmental conditions like high humidity, as this will make the cure process faster. In cooler or dryer conditions, you can expect a cure time of up to 48 hours which is the typical drying or cure time for silicone caulk.