Excel 435 HD fit out from scratch

[jeffstevens763@g]

i have 12 coats of wax on the plug now and all buffed up ready for the PVA.
pics of the PVA, applicating sponge and a sample on a piece of untreated timber I'm quite happy with the finish on the timber it will hide the very minute scratches on the plug. i want a descent finish but not shiny it'll stick out like a sore thumb too shiny in any case I'm using matt PVA on the cast for the boat trying to get somewhere near the tube fabric finish.

[jeffstevens763@g]

so got the PVA on I'm delighted with the finish although it shows the scratches up they have no depth and the PVA seems to overcoat the blemishes and scratches in any case, bearing in mind i will have the front cut out for chartplotter etc and hatches in the top and the long side for access it should look ok.
I'm waiting for some PPE from screwfix so when that comes i will do the glassing up of the mould.

[jeffstevens763@g]

A few more pics of the mould.

[jeffstevens763@g]

the process explained for glassing up.

so got the gel coat on brushed this took over night to get tacky, then resin coat and the first layer of 100g chopped strand matt, then two layers of 300g matt. i let that cure then did the strengthening webs i used cut down bits of the book case more for just holding the glass up to the create the web i used scraps of matt for this that i had from other jobs. after them i strengthened the edges up with resin and 3/4 inch chopped strands to make a paste, its not pretty because it nigh on impossible to get a smooth finish and all the air out, but having said that i only want strength so i can prise the mould off the plug if needed and for the cast i will have a strong edge to work to when i trim the cast. when it was all dry i trimmed the edges and sanded the lot down smooth, cleaned it and they a final coat of resin for a smooth ish finish.
i took the valve out of the tyre inflator cleaned the wax out and filled with water this will break down the PVA release agent ready for splitting the mould off the plug in a day or two.
my next step is to restrain the mould so it doesn't fly when i pressurise with air this might be fun we shall see although it will have pressure it wont have volume and the taper on the plug means it will soon loose its seal. if this doesn't work ill pull out the inflator and fit my bottle jack in there but i will beef up that area on the mould to save damage.

[36valley]

It looks like you've let some of the area around the flanges get quite hot. When you make the component try to not build up any areas too thickly in one go. You may find the heat causes shrinkage and pull marks in those areas.

You shouldn't need to leave the gel coat over night to get tacky, it should be ready in two or three hours.

[jeffstevens763@g]

Originally Posted by 36valley

It looks like you've let some of the area around the flanges get quite hot. When you make the component try to not build up any areas too thickly in one go. You may find the heat causes shrinkage and pull marks in those areas.

You shouldn't need to leave the gel coat over night to get tacky, it should be ready in two or three hours.

thanks for the tips bud to be honest I'm doing this in a cold shed with only a fan heater so the flash off is taking a long time and i was running late into the evening on the gel coat.
as far as I'm aware it didn't get that hot it looks thick but its on a curve so only about 5mm

[jeffstevens763@g]

So i got the mould off the plug not in the way i wanted by air but by breaking it out.
as i said first mould I've built and i would not use softwood again although it looked a good finish the mould has grain lines i don't know if the glass fibre has pulled in to the soft wood or not, the dura build hasn't soaked into the wood either. i would use hardwood ply if i built another for sure. its not the end of the world for the finish i want but i would have it sprayed if i wanted a mirror surface, ill have a look when i cast the console. the good thing is its a lot lighter than the HDPE console i have now. I've got an small area to gel up where i damaged the flange then its back to waxing the mould inside and beefing up the bottom on the external side the air pressure was quite powerful and started to bow the bottom hence breaking out the plug

[36valley]

Wooden plugs breaking up when removing moulds from them is quite common.

Reading your description of making the mould I'm not sure if you gave the plug a second Gel coat.

If your looking to have a Gel coat finish on the console then make sure you apply two good Gel coats to the mould. This will hopefully give you enough thickness to wet and dry out the worst marks and buff back to a decent finish.

If you can, also pigment the lay up resin as that will help if you have to flat back any marks.

The best thing is to spend the time to make the mould as perfect as you can and hopefully you won't have too much making good to do on the console.

[jeffstevens763@g]

Originally Posted by 36valley

Wooden plugs breaking up when removing moulds from them is quite common.

Reading your description of making the mould I'm not sure if you gave the plug a second Gel coat.

If your looking to have a Gel coat finish on the console then make sure you apply two good Gel coats to the mould. This will hopefully give you enough thickness to wet and dry out the worst marks and buff back to a decent finish.

If you can, also pigment the lay up resin as that will help if you have to flat back any marks.

The best thing is to spend the time to make the mould as perfect as you can and hopefully you won't have too much making good to do on the console.

Your right I only did one gel coat 36V I know I should have done two for this reason still it is what it is I will do two on the console. I'm going to try my hand at spraying the Matt PVA hopefully that will give a finish a bit like the tube fabric. I've got to make a floor for the inside so I'll lay that up on a sheet of HDPE to how it turns out using the same method.

[36valley]

Originally Posted by jeffstevens763@g

Your right I only did one gel coat 36V I know I should have done two for this reason still it is what it is I will do two on the console. I'm going to try my hand at spraying the Matt PVA hopefully that will give a finish a bit like the tube fabric. I've got to make a floor for the inside so I'll lay that up on a sheet of HDPE to how it turns out using the same method.

When you spray the PVA you need to get an even coverage, as in it all looking the same colour, no heavy shading or light patches. The finish you see on the mould will be mirrored on the component.
Spraying into a mould with deep sides can be trickier than you think.

As you say practice on the floor section first.

[jeffstevens763@g]

Originally Posted by 36valley

When you spray the PVA you need to get an even coverage, as in it all looking the same colour, no heavy shading or light patches. The finish you see on the mould will be mirrored on the component.
Spraying into a mould with deep sides can be trickier than you think.

As you say practice on the floor section first.

Yea been thinking about spraying I've go a mate who sprays for a living might contract this out me thinks

[jeffstevens763@g]

I decided to rub the the mould down to 1200 grit i wasn't happy with the finish although I'm going for a matt finish with the PVA to suit the boat, i was lucky that i had enough gel coat on to get a decent finish its not perfect and the pictures make it look worse that it does to the eye but I'm happy that i will get what i want.
i strengthened the base up with a solid bottom and glassed over it, i had some flow coat left from a previous job so i coated the outside of the mould it looks better and its getting rid of old materials.
so the next few days will be waxing 12 coats i probably don't need them with the PVA coating but it will make the surface finish better and be a release in its self as some don't use PVA i understand.
I've got to fit the tyre inflator too yet but that's just drilling a hole and poking it through

[jeffstevens763@g]

36 valley when i get the finished cast done and I've shaped the flanges can i use gel coat on the edges spraying with PVA over it to allow it to cure?

[36valley]

Originally Posted by jeffstevens763@g

36 valley when i get the finished cast done and I've shaped the flanges can i use gel coat on the edges spraying with PVA over it to allow it to cure?

To seal the edges use flow coat. If the flow coat is the wrong colour then add a 'small' amount of liquid Paraffin wax to gel coat.

I've never used gel coat with pva over it so don't know if that will work.

If the flanges are sitting on the tubes, depending on the thickness I would use a rubber edge trim to make them both tidier and kinder to the tubes.

Assuming I've understood how the console fits correctly.

[jeffstevens763@g]

Originally Posted by 36valley

To seal the edges use flow coat. If the flow coat is the wrong colour then add a 'small' amount of liquid Paraffin wax to gel coat.

I've never used gel coat with pva over it so don't know if that will work.

If the flanges are sitting on the tubes, depending on the thickness I would use a rubber edge trim to make them both tidier and kinder to the tubes.

Assuming I've understood how the console fits correctly.

Thanks for the reply I can get 100 ml of wax about £3.95 so cheap as chips just wondered if you had used PVA I might just buy flow coat and coat the inside too.
Yep going to use some foam, done that before works well

Cheers jeff

[Steve509926]

Hi Jeff,

Will the mould be reusable?

[jeffstevens763@g]

Originally Posted by Steve509926

Hi Jeff,

Will the mould be reusable?

I think so Steve I'll know when I get the first one out mind it is easy to repair, it won't have a pro shiney finish but I don't want that if I did I would have it sprayed with I think it's duralac twin pack. Using the PVA does give a decent finish to my mind I'm looking at the boat fabric texture and think a shiney console will look odd

[Steve509926]

I agree, a high gloss finish wouldn't look right on the textured finish that Excel use. I think the tube diameter on you 435 is larger than my 360 otherwise I'd be interested in buying one from you

[jeffstevens763@g]

The console has to have some rubber to stop chafe on the tube Steve,you just increase the the thickness of that rubber to take up the difference for smaller tubes we'll see how it goes I'll be happy to knock you one out at cost for materials or you could borrow the mould.

[Steve509926]

Thanks Jeff, be really interested in that