Hints and Tips



Side window leak repair (non-removal)

- SO42DS


• Tape areas to be protected from caulking removal tools

• Remove all accessible existing caulking from acrylic window & cabin FRP. I used a dental pick and curved knife

• Clean all areas with acetone or denatured alcohol

• Jet air blow to remove any dust or loose particles

• Re-tape top edge of window and cabin side – Frog™ tape (Green) for best edge control, but cover a wide area as this stuff can be messy.

• Apply the clear Sika Aktivator™ 205 (Formerly Sika-Cleaner™ 226) to all accessible PMMA and FRP surfaces with an artist brush. Allow cleaner to dry 10 minutes but not more than 2 hours before applying 209D primer.

• Primer window side & FRP CAREFULLY & SPARINGLY with Sikaflex™ primer 209D including inside edge. This is black and very viscous so, if you get it on any surface other than what was intended, clean if off immediately. Allow cleaner to dry 10 minutes but not more than 2 hours before applying Sikaflex™ 295UV. I contacted Sikaflex on how to remove the dripped area of primer. They told me I had to remove it within two hours with MEK (Not available to the public in the USA). This information was NOT listed on their data sheet.

• Fill gaps completely (slightly overfill) with black Sikaflex™ 295UV. Keep the work area shielded from direct sunlight and temperature extremes 50°~95°F or 10°-35°C.

• Smooth with double rubber gloved finger against the tape. Refill areas not smooth. You have less than an hour to work with this material.

• Remove tape before the 60 minutes setup time

• Cover area to prevent rain or condensation from getting to Sikaflex™ areas

• Cure 24 hours to touch. Allow minimum of 1-week full cure prior to total water immersion situations.

• If you need to repaint the black outside paint on the window, mask and sand area to be painted with 400~600 grit wet-dry sandpaper. Wipe with denatured alcohol and paint the window areas only with Krylon™ Fusion© for plastic. I did one very fine spray, let dry for 15 minutes and then did another slightly heavier coat. (I did a few practice runs on a scrap piece of plastic first to test the spray pattern and when to remove the tape.) I used the entire can since this paint is somewhat translucent through about 4 coats. Remove the tape carefully and within 1 hour after the final coat. I am happy with the uniformity of the spray to block the sun’s UV, but I was expecting a high gloss finish. I’m going to sand 600-800 grit & add another series of coats in a few months after the paint has had time to cure and weather harden.


NOTE OF CAUTION - I made the mistake of spraying the vertical Sikaflex™ 295-UV joint with the Krylon™ paint. DO NOT PAINT this surface as it soften the Sikaflex™ 295-UV surface making it tacky with paint & Sikaflex coming off on my fingers. It seems to be slowing curing, but I’ll have to wait about 1 month to see if it will fully cure. If not, I’m going to have to pull the caulk and re-caulk. Overall, I am pleased with the project. It doesn’t leak and it looks good.


Brent Meyer - Tafika II - SO42DS