Gelcoat problem(picture attached)

[needhelp]

I do normally lay the mould on its side but this isnt probably enough if you are saying air needs to move around it...i will purchase a small fan and blow it into the mould as its drying...would you need to do this for just the gelcoat stages or for the laminating too....many thanks

[tunnels]

Originally Posted by needhelp

I do normally lay the mould on its side but this isnt probably enough if you are saying air needs to move around it...i will purchase a small fan and blow it into the mould as its drying...would you need to do this for just the gelcoat stages or for the laminating too....many thanks

Before you buy a fan just put it in a door way where there is a movement of air so the styrene will spill out . Its something most people never ever think about . Styrene is heaver than air so will stay in hollows . Have the same problem making decks with lots of deep hollows in them . Just need to get a airline an blow then a couple of time during the gel and hardening if the gel coat .

[needhelp]

Just to update...i purchased a fan to which i set this into the mould blowing air across it while the gel was drying...the finished product has come out perfectly...many thanks to everybody who answered you were a great help

[Herman]

Good to learn that you have solved your problem, thans for the feedback.

[ondarvr]

Its great that you updated everyone here with the outcome, many times people get an answer or two and then we never here from them again to know if it helped.



Mixing a 50/50 blend of resin and gel coat may work in some situations, but proper technique will typically trump it.

Depending on the casting resin you choose, it may appear to have less shrink because it has a suppressed exotherm, really what you have is just an under cured mix that won't have the same physical properties as would if done correctly. It won't shrink as much in the beginning, but when its exposed to heat in the future the surface may distort a great deal.

Or, if the resin is a DCPD, or DCPD blend, it may have less shrink, it will also be more brittle, less UV resistant, and the big downside with this mix can be bonding of the laminate. DCPDs cure very well on the backside and this can create bonding issues in many applications.

Another issue with mixing is gel coat bases is they tend to be high quality resins designed for UV, blister and crack resistance, casting resins are formulated many times with a different set of goals.

Painting the parts may eliminate some of the issues, but unless the parts being made don't need to meet any performance standard you're risking failure and a big claim in the future.