Hi,

You'll certainly need to 'surface' the foam with something to seal it, harden it and allow it to be polished up to a high standard. On its own the foam is not a suitable release surface.

For coating the foam pattern I would suggest epoxy coating resin and a layer of lightwight 163g glass coth and then additional applications of the epoxy coating resin with microballoons and fumed silica to make it thicker and more sandable. You should then be able to flat and polish this to a high standard ready to take your moulds off.

-- Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Hi Matt, just a fast question:

If I have made a pattern of PU foam, can I use it directly with Uni-Mould System or should I put some putty all over the pattern before I apply the release agent? In that case which would be the best?

Waiting for your reply, thanks!

Regards!

Hi there,

Completely understood, and of course you are completely right. I just try to have the project as planned as possible and to know which of the ideal ideas in my mind are possible in the practical part of the project.

Thanks again very much for your attention and I will inform how is the project going.

Best Regards!

Hi,

OK, I understand now. Well, it's possible but you're certainly making a lot of work (and causing a lot of problems) for yourself! - We get a lot of questions on the forum and in emails about embedding logos, signitures and the like, often in very adventurous ways and if I could give one piece of advice to aspiring composities manufacturers (particuarly those with little experience) it would be to hold-off with the fancy logos until you've got your product coming out spot-on; particlarly if there's a good chance that the inclusion of said logo might cause production problems or actually end up being its downfall.

In your idea here you're creating quite a detailed area of the moulding with right angled corners where fibre bridging or bag bridging is likely to be a problem. If that doesn't end up being a problem then it still may well cause a re-lease problem unless the sides of the recess are sufficiently tapered. Finally, if that all goes to plan and it doesn't bridge and it release OK from that section without taking a chunk out of your mould or part then you are left with the task of 'embedding' the logo and then blending that embedding resin into the surrounding resin without it looking a mess. I think for this last part if you plan on lacquering the whole case afterwards then this might be feasible but if you just want to blend nicely into the surrounding flat material then it might look messy.

I never want to stop people from having a go at something they want to do but my advice would certainly be to concentrate on getting the case right, where you've got enough to think about, and worry about embedding logos when your carbon fibre cases are the hottest ticket in music!

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Hi again,

1. Ok, I understand, I am going to use the Uni-Mould System, so then hope will be Ok.

2. I try to rephrase:

I want to add a logo to the case, so instead of attaching the PVC plate with the logo to the case throught adhesive application, my idea is:

To make a hollow where the plate could be accomodated in the pattern so, that I will get the same hollow in the final carbon fiber case. When the case is cured and finished, can I then put the PVC plate inside the hollow and then fill again with epoxy resin? I would like the logo remains not over the case in the surface, I would like to have inside the proper case.

I hope you can understand what I mean. The orders of materials from inside the case would be: carbon fiber layer, epoxy resin, PVC plate and epoxy resin. After that, I would sand paper the last small part of epoxy resin and polish it to make an even surface. I attach an image for better understanding.



Thanks again for your attention, and waiting for your advices.

Best Regards!

Hi,

1. I don't know if I had a mistake, but the Foam supplier recommended me to use a polyester putty, because the foam is hard but porous. I bought and applied one layer of polyester putty, but in the can is written that this putty is also porous, and another layer of a complementary putty should be applied on the top of that.
Do you think is necessary? Did I make a mistake already in the process?

I'm not familiar with the filler/putty that you're using to coat your foam pattern so I honestly don't know if it's right or not. Remember that you'll now have a polyester surface on your part and so you need to be very careful about what you make the mould from in order to ensure that it will release OK from the pattern. Our Uni-Mould system would be OK because it used a vinylester gelcoat and so it will release fine but epoxy tooling gelcoat would not.

Regarding your logo I'm afraid I can't quite understand what it is that you want to do so I'm not sure what advice I can give you. Maybe try re-phrasing?

All the best, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Dear friends,

I have started now with my project and couple of questions have comen to my mind. Hope you can help a bit with your valuable knowledge as usual.

I have made a pattern of Foam, and I think is quite ok, but about the nexts steps:

1. I don't know if I had a mistake, but the Foam supplier recommended me to use a polyester putty, because the foam is hard but porous. I bought and applied one layer of polyester putty, but in the can is written that this putty is also porous, and another layer of a complementary putty should be applied on the top of that.
Do you think is necessary? Did I make a mistake already in the process?

2. I was planning to add a logo to the case. I have contacted with a serigraphy supplier for making a PVC plate. My idea is to make a hole in square shape in the foam's surface, so that when I try to get the case, there is the same squared-hole on it. The question is: Once the case is fully cured, can I add the PVC plate in the squared-hole and add some extra epoxy resin for holding it to the case inside the case surface, and then sand paper the area and polish it for leaving a very smooth surface with the logo inside? The idea is that the PVC plate remains inside the surface of the case, not on the top of the case, sorry if I don't explain myself properly. 

Hope you can help me with these questions.

Thanks, hope you are spending a great summer!

You're welcome. I look forward to seeing how the project progresses. Be sure to post some pics in the 'project showcase'.

All the best, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Hello to everybody,

sorry for my late reply, but I have been quite busy.

Thank you very much for all your advices, I will keep in mind all the great info you gave to me!

About getting a case and copy it, I didn't mention that this case doesn't exist, I was looking for it for buying it for my instrument but I couldn't find it, so I decided to make one.

My first step will be to get the foam, so I will keep you informed about how is the process of the case going!

Thanks again!

Hi,

Thanks for your detailed post and sorry for the delay in getting back to you. Warren has given some good advice.

I'll try to answer all your points:

1. I agree entirely with Warren. If you can 'copy' an existing case (and you're happy with its size/shape/design) then do that - use the case as a 'pattern' and make a mould using that pattern. This will leave you with a female mould that's the right shape for your instrument and with a good finish on the inside (which will become the outside of your part).

If you can't find a case like this then you should certainly look at making a 'pattern' for the case. I would imagine this pattern would be a simpler, smoother shape than the exact shape of the instrument and also be larger (maybe considerably larger) in order to accomodate the foam lining that you will use inside the case. For this reason, applying anything to your instrument itself is not neccessary and would not really help, far better to start from scratch making a foam or MDF pattern and then make moulds from this pattern (like you would if you were copying an existing case).

2. Again, Warren is spot-on. Kevlar is a reasonable insulator and because of its VERY high tempertaure tollerance it does get used in some insulation applications but this is always for protection from very hgih heat, not because Kevlar has a particuarly high U-Value. At the thickness you would be using the Kevlar its thermal insulation performance would be pretty insignificant. For thermal insulation (and shock protection) foam would be a very good idea.

Don't worry about the compatibility of the foam with epoxy because you'll be making the case first and then bonding the foam into the case, which you can use any contact adhesive to do.

3. As above, I think foam is a good idea. Profiled polyether foam ('eggbox foam') is great for lining cases and suchlike. You could also consider 'memory' foams. We don't supply these materials and they're quite bulky so I would suggest just checking with some local suppliers.

4. This one's more of a question of what system you can find. If you've got two surfaces that come together pefectly then you should be able to find an off-the-shelf sealing system somewhere (although I can't recommend anything myself). Try checking with seals suppliers or silicone extruders to see if they have a section that would suit. My guess would be a silicone or rubber section that's bonded to one side fo the case and then accepts and seals with the other side of the case shell.

I hope this helps and look forward to working with you.

Best regards, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales