Cockpit recaulking - how to deal with edge seam near gelcoat?

[mibbal]

Hello Mates,

I'm preparing for complete recaulking of my teak cockpit with TDS SIS440.

Any experience based advise on how to do seam at the edge, between last teak plank and gelcoat (as shown on attached picture)?

I understand how to deal with seams between planks, but this one on edge is a bit tricky for me since is would not be possible to sand it.
Should I use finger or special putty knife (for bathroom silicone) to form the seam?
Can I remove SIS440  (when not cured) from gelcoat with acetone?

[Yngmar]

Masking tape and finger if you want a concave seam, or a wooden stick if you want straight. White spirit should be sufficient, acetone probably not ideal. Have a big bucket/cardboard box with bin liner and brick in the bottom to toss in the masking tape without dripping everywhere.

Then don't step into it. Good luck!

[Ailatan]

Acetone also worked for me.
Take into account that TDS SIS440 shrink a lot so even if you use a straight tool you will finish with a concave shape

[Odysseus]

I agree white spirit is good for cleaning, not as aggressive as acetone. However i used CTI sealent, i find it does not melt in hot sum.

Odysseus
Bav38

[mibbal]

Thanks Folks for the advises!

Should I sand after removing old caulking (before applying new one)? In some sources it is recommended to do so, but I'm not sure why. I guess sanding before application of new caulking may help to make surface smooth. Any suggestions?

[marioxp]

I would not advise you to sand before caulking. Because you will definitely have to sand after caulking.
I masked everything with tape, after I applied the caulk, I leveled the caulk with a credit card.  Immediately, while it was still fresh, I removed the masking tape.  I am very satisfied with the result.  I used a Sika 290DC.
I just had to sand a little.

[Ailatan]

I sanded the seams before applying TDS for two reasons: first because TDS is completely different product than the old one and second because I changed the original black colour for white.

[N44rag]

Is it best to fill the gaps between the teak first and let that cure before doing the perimeter seal later, or better done in one go?

Martin

[Happysailor]

I used the masking tape as suggested as well and it depends how clean you can work. Last time I did it in 1 go, masking the seams and trimming the tape exactly to the shapes with a Stanley knife. It also can be done in 2 steps. The compound is still fresh and will easily connect in the 2-step seem.