WHAT TOOL DO I USE?

[Clivevon]

A gelcoat planer is a tool used to strip gelcoat off the underwater hull as part of an osmosis repair.

[zengirl]

Originally Posted by Don C L

Remember you don't have to remove the blue gelcoat to prepare it for painting. Once divots are filled and faired and it is sanded, a good primer will work wonders. I'm using a polyurethane enamel so I am using Pre-Kote, a one part primer and even that is very good at filling and covering. The two part primers are even better.

Thanks, this is the route I'm taking after all.

[Kerry1]

Originally Posted by zengirl

I am going to replace windows in the next few weeks. I don't want to use screws like in the picture. Can I just use a good sealant and what brand do you suggest? (not 3m5200). Also, I want to get rid of that blue gelcoat and the crazing. I read somewhere there is a planing tool to strip it with. Do you know the name of one that will do the job? Thanks for all your input.

The following youtube link shows a tool for removing gelcoat. Although most applications involve the removal of gelcoat from the hull, it will work of course topside. .The video shows a UK made tool, whereas I understood there was also one developed in NZ. This is fairly drastic treatment for what seems essentially cosmetic, but hey, we all like to look our best!

https://youtu.be/pomiK0D4kUU

Right now we are lying in a marina next to a nice boat which has the same issue with blue gelcoat and the rest of the white topsides are fine, it must be an issue with blue. Maybe the dark colour absorbs more heat and expands contracts more than surrounding white which sets off tensions eventually causing crazing. Our blue stripes havn't crazed but is def. faded. Good luck with your project.

[adjo]

Originally Posted by JPA Cate

@zengirl,

If you're replacing with acrylic panels, their expansion is 25%, which is why you need serious clearance holes. It is the too small size of the clearance holes which has led to the cracking.

Ann

25%!!
I think something was "lost in translation" here, Ann.

Acrylic expands with increasing temperature by approximately 0.075 mm / m / K,
This means that a 1 meter acrylic panel will become 1.5 mm longer if the temperature rises 20 degrees C.

[BruceS]

Local chap was using Sika to install solar panels on motorhomes until he realized very hot days released the bond. He now uses a Simpson product. Read up on temperatures for these products!!

[pelagic71]

My only input would be to say that you should not simply squeeze the caulk out of a tube, put it in a container first and mix it well with a putty knife to get the air out. Then tighten the screws down almost all the way, leave it to set up, then finish tightening.

[zengirl]

Originally Posted by pelagic71

My only input would be to say that you should not simply squeeze the caulk out of a tube, put it in a container first and mix it well with a putty knife to get the air out. Then tighten the screws down almost all the way, leave it to set up, then finish tightening.

Thanks for this advice, I never would have known. I just love CR!

[zengirl]

Originally Posted by Kerry1

The following youtube link shows a tool for removing gelcoat. Although most applications involve the removal of gelcoat from the hull, it will work of course topside. .The video shows a UK made tool, whereas I understood there was also one developed in NZ. This is fairly drastic treatment for what seems essentially cosmetic, but hey, we all like to look our best!


Right now we are lying in a marina next to a nice boat which has the same issue with blue gelcoat and the rest of the white topsides are fine, it must be an issue with blue. Maybe the dark colour absorbs more heat and expands contracts more than surrounding white which sets off tensions eventually causing crazing. Our blue stripes havn't crazed but is def. faded. Good luck with your project.

Mine is just like this, the rest of my topside is fine. All Freedom 32's have this blue strip and I think you may be right about the blue having an issue, maybe with the initial application. Thanks.

[CHM]

Clean off the old adhesive well. Use Dow 795 which is a commercial glazing compound. This is the best for what you are doing. The screws are only there to hold a large panel in place while the 795 cures which is a 30 day full cure. Then you need to back them out so they are barely finger tight. If they are too tight, the material will expand and crack the plexiglass. You can remove them entirely if you want and just seal the holes with a little more 795.