I've watched a lot of boat and fiberglass building and repair videos over the past decade, and I can honestly say that Andy Miller of @BoatworksToday is about the best there is in terms of content (info & tutorials) and delivery.
As someone who has done thousands of repairs over many decades as a professional fabricator, I can say that, apart from impacts, star cracking/crazing is a result of two things; 1. The laminate is too thin (or too dry in a minority of cases) causing the laminate to flex excessively. While gelcoat doesn't want to flex, especially as it ages. 2. The gelcoat is initially applied too thick (this occurs in corners or difficult to spray areas). The thicker the gelcoat is, the less it will be able to flex along with the laminate. This is exacerbated by time. As the gelcoat ages it becomes more brittle and less able to flex as the styrene leaches out over time. Without styrene, the resin in the gelcoat becomes brittle. This is why a gelcoat which has been applied too thick will usually not show up as a problem until after a few years when the styrene begins to evaporate. Cheers
Got bless ...watching you like crazy because I need (know how) from you... can't get your experience...but I'm sure now I can handle some of it....working on my 84 Cobia on UA-cam you the best
If the gelcoat was thin can you actually just brush on a layer of resin or if not this 50g mats which are made it improve the surface after eg laminating with biaxiale 450g mats? That gives you a much better surface than with the chop strand mats.
Brushing on a layer of resin would fix the crazing short term. However, over time, the cracks would start to appear again. We recommend following this video to ensure the crazing will not come back!
@@TotalBoat but why. If it is like you explain that eg the not enough resin in production that resin would fill that voids and stabilize the surface if that’s just in the first layer of the fiberglass means the material underneath is still strong. When we done my underwatership The fiberglass expert repairing the boat showed me with leftover resin how duarable just 1mm of the plainsur vinylester resin was…just to break 1mm pure resin needed already big force and that would have stabilized the surface definitely enough. Different with the polyester resin, that was easy to break, but vinylester you can still gelcoat directly over will do it. If cracks come then the whole thickness had cracks and need to be stabilized from both sides.
@@TotalBoatwhat if the cracks were not in a corner and were caused by the previous guy letting it bang against a dock causing the cracks. Would you still want to reinforce the fiberglass?
Lots of great old boats still floating around out there with plenty of crazing to repair! Lucky people with new boats can wait a few years or decades to watch this video.
I've watched a lot of boat and fiberglass building and repair videos over the past decade, and I can honestly say that Andy Miller of @BoatworksToday is about the best there is in terms of content (info & tutorials) and delivery.
Seeing Andy on TotalBoat's channel is awesome.
Shows how seriously TB takes their products and customers, only the best to showcase.
“Start the itchy scratchy show!!” Love that statement 😅
As someone who has done thousands of repairs over many decades as a professional fabricator, I can say that, apart from impacts, star cracking/crazing is a result of two things;
1. The laminate is too thin (or too dry in a minority of cases) causing the laminate to flex excessively. While gelcoat doesn't want to flex, especially as it ages.
2. The gelcoat is initially applied too thick (this occurs in corners or difficult to spray areas). The thicker the gelcoat is, the less it will be able to flex along with the laminate.
This is exacerbated by time. As the gelcoat ages it becomes more brittle and less able to flex as the styrene leaches out over time. Without styrene, the resin in the gelcoat becomes brittle. This is why a gelcoat which has been applied too thick will usually not show up as a problem until after a few years when the styrene begins to evaporate. Cheers
I have done a similar thing with dremeks, drills and various grinding bits. Loving the small gauge belt sander approach. Slick!
Thanks, allways no-nonsense and very informative. Love it- Cheers 🍺
Got bless ...watching you like crazy because I need (know how) from you... can't get your experience...but I'm sure now I can handle some of it....working on my 84 Cobia on UA-cam you the best
Great video as always.
Excellent!!!
Glad you enjoyed the tutorial!
I so needed to see that, thanks!
If the gelcoat was thin can you actually just brush on a layer of resin or if not this 50g mats which are made it improve the surface after eg laminating with biaxiale 450g mats? That gives you a much better surface than with the chop strand mats.
Brushing on a layer of resin would fix the crazing short term. However, over time, the cracks would start to appear again. We recommend following this video to ensure the crazing will not come back!
@@TotalBoat but why. If it is like you explain that eg the not enough resin in production that resin would fill that voids and stabilize the surface if that’s just in the first layer of the fiberglass means the material underneath is still strong. When we done my underwatership The fiberglass expert repairing the boat showed me with leftover resin how duarable just 1mm of the plainsur vinylester resin was…just to break 1mm pure resin needed already big force and that would have stabilized the surface definitely enough. Different with the polyester resin, that was easy to break, but vinylester you can still gelcoat directly over will do it. If cracks come then the whole thickness had cracks and need to be stabilized from both sides.
Great!
Thanks for watching!
Are they structural or cosmetic? Does crazing leak?
Typically, crazing is cosmetic. However, over time, if left, the crazing can become a structural issue and may even leak.
Could you just sand the cracks back and then gel coat without going all the way through to the fiberglass?
If you do not sand the cracks completely back, they will come back over time.
@@TotalBoatwhat if the cracks were not in a corner and were caused by the previous guy letting it bang against a dock causing the cracks. Would you still want to reinforce the fiberglass?
@@thisisfun887 Definitely!
Not every boat. I don't know of any on by 32 year old boat. Just got done buffing and polishing every bit of gelcoat.
Lots of great old boats still floating around out there with plenty of crazing to repair! Lucky people with new boats can wait a few years or decades to watch this video.
Haven't been here for a while but you sound different.