laying up jel coat in a mold ...Disaster>>Help

im laying up in a mold ive made out of white faced chipboard 3 waxes and one pva ( L shaped plant pot 3mx2mX500 that Im going to spray paint a design on later ) basically ive just realized i should of put 15mls in the mix ..not 3mls in the 1st jel .. can i put another jel over at a slightly hotter mix to try aid the 1st coat . disaster !!.. not sure what to do , help appreciated

ive slapped my self for not doing a test run

 

keep it simple !! simple is always best !!!

ok lets talk percentages of catalyst ??
Please keep everything simple and basic !!
The coverage is close to .6 kg of gel coat for every sq mtr of mould surface !!

First coat of gel coat over any mould is advisable to be 1.5% of catalyst one kg of gel coat needs 15 mls of catalyst .

Second coat of gel coat over the first coat about 4 hours apart should always have a higher ratio of catalyst usually 2.0 % !!! this is so it will gel off quickly and hopefully will not react with the first layer you applied .

The gel time for the first coat should have been close to about 30 minutes at the 1.5% of catalyst .

The second coat gel time should be shorter , about 20 minutes !!
Before you glass over the gel coat look and search for suspected thin places !!
The glass needs to be resin rich and well rolled out so there is absolutely no air bubbles of any sort .
A small trick is to add a little gel coat with the resin and this will serve as a even better depth of colour and definite wont see any thin places
If you already have a hot brew of gel on the mould now make the second coat the same ratio but add a small amount of resin to your gel coats and roll it on with a paint roller . its quick its easy and make sure you cover every where including edges !! the resin gives a slightly smoother surface to glass over and makes it easier to use . !!
have any more problems just ask

 

If you intend to paint over the gel coat at the very worst that can happen would be the panel pre releasing its self off the mould and having distortion here and there .
When working with any 2 part products including 2 pot paints The ratio for catalysing is really really important !!! It can be raised a little and lowered a little but not much either way from what ever was recommended by the supplier you got your products from !!

I cant be 100% specific as each country is different and products vary so much !! follow the instructions given !!!

The old saying applies !!! when all else fails read the instructions !!

 

Tunnels is this your plan for rolling "hot" gel only? can it be sprayed in this fashion from a dump gun? what is the total mil. thickness of all the gel coat layers?

 

The info you seek has already been posted !!

Read the instructions a couple of post back all the answers are there . Hot mixes are always potential problems caused by shrinkage caused by hot mixes be it gel coats or be it gel coat use what the supplier recommends and also the catalyst type recommended as well. I am a non believer in hot mixes full stop . !! slightly faster brews yes but never hot mixes !!

 

All glassing and Gel coating you need to stay within acceptable limits of what is stated but all manufactures . Being smart and exceeding manufactures recommendations of catalyst ratios you are leaving yourself wide open to problems play by the laid down hard and fast rules you get what you want and everything works like it should . shrinkage is kept to a minimum level and the correct hardness is achieved .
Step outside the boundaries intentionally you get what you deserve !!Usually failure and problems galore !!

 

But for the topic starter: You missed a lot of catalyst. This will leave the gelcoat half-cured, causing all kind of problems.

Best is to laminate a thin layer of glass behind it, then rip it out.

Do a quick re-wax, re-apply PVA, then re-apply gelcoat. And this time I bet you will be keeping a close eye on mixing ratios.

I am terribly sorry if this is not what you want to hear, but keep in mind you are learning with a relatively cheap gelcoat. Some people learn by chiseling carbon boats out of a mould.....

 

Some more basics !
Gel coating and fibre glassing is not complicated but there are few basic things you need to adhere to !
Moisture from humidity or what ever can slow things down a lot !! so make sure everything is dry !!! .
Temperature is another thing !! if the weather is not warm enough it will slow the gel times and can lead to a few problems !! cure is not the same as gel time ,just because its hard does not mean its cured !!
So your working environment is really important . dry and warm and clean and use the recommended catalyst at the ratio specified by the manufacture and you wont have to may problems with the materials you are using !!. This applies to any and all fibreglass work !! no matter what resin or what glass you using or how big the job .
WEIGHT THE RESIN OR GEL COAT !! Small quantities are a problem si make sure you have a measure for the catalyst that is well marked and easy seen . A plastic syringe can be a really easy way of measuring smallish amounts !and digital scales that can read 0.00 scale to be accurate !! small amounts kitchen scales covered with plastic are useful ,Bath room digital scales for bigger amounts or plastic container with a scale of measurements marked on the inside !! . mixing small amounts you need to take your time and mix 100% always even bigger amounts mixing is very important . if you use a paint stirrer in a battery drill but careful not to aerate the mix to much and leave stand a couple of minutes when you finished to let the bubbles come to the surface before you start to use .
Most everything Iv said here is just plain common sense !
WARM AND DRY !!,
CORRECT RATIOS !!,
ACCURATE MEASURING !!
PROBLEMS GONE

 

You risk the whole thing alligating - regelcoationg over the first coat, you risk a pricy monkey -phuck. You should blow it out with a air line and start over,, the truck bed liner kit guns work great for spraying the gel on like stucco--without any thinning with expensive styrene, ( you should not use acetone for thinning, but I have done it for yrs). The thing you are calling a mould is really a "form". Moulds are production tooling in my world, period.
I see all kinds of guys here refiring to all kind of~ one off~ forms as moulds.

 

whats the problem ??

If you still thinking what should you do ,its a little late !!
just brush a hot coat of resin over the whole gel coated area and once its hard peel it off and get back to square one and stop messing about ,
You stuffed up by not thinking about what your doing so live with it !!
we all make mistakes wouldn't be the first and wont be the last ! learn from it !!pick up and get on with it !!

 

The problem of adding styrene is that you can end up with a larger amount of residual styrene, which causes yellowing over time.

Adding acetone, like all gelcoat manufacturers do for formulating spraygelcoat, has the disadvantage that you need to be able to finely mist the gelcoat (needs a good pump), you need some skill to keep the minimum required distance (the acetone should evaporate during its path towards the mould) and sprayed in thin layers, as to give the aceton the chance to evaporate further. Geltime should be not too short, for de-airation and acetone evaporation. Final cure should be good, as to prevent alligatoring. All in all, it means having a decent temperature in the workshop. (consult datasheet of your gelcoat, never a bad idea)

 

feed back is required !!

ok tell us at what stage are you at now with what you were doing ???