|
dcfoster
|
|
|
Group: Forum Members
Posts: 32,
Visits: 100
|
Another reason Im glad I found this forum. Thank you again Hanaldo for your help. Thumbs up to you good sir!  Hanaldo (20/05/2015)
While you technically COULD do it, you need to know what you are doing, you need to be able to look at the data sheet, find out what's in each resin/hardener, and then adjust the mix ratios to make it work. Not quite as simple as it sounds, given most manufacturers won't disclose the composition of their products because they are commercially sensitive. You also need to remember that these are very complex chemicals, and manufacturers have spent a lot of money on R&D to make them. If you fancy wasting a lot of resin, you could do some testing. Even if you find a mix that cures, you will have no idea what the properties of the cured resin are.
|
|
|
|
|
Hanaldo
|
|
|
Group: Forum Members
Posts: 2.5K,
Visits: 28K
|
While you technically COULD do it, you need to know what you are doing, you need to be able to look at the data sheet, find out what's in each resin/hardener, and then adjust the mix ratios to make it work. Not quite as simple as it sounds, given most manufacturers won't disclose the composition of their products because they are commercially sensitive. You also need to remember that these are very complex chemicals, and manufacturers have spent a lot of money on R&D to make them. If you fancy wasting a lot of resin, you could do some testing. Even if you find a mix that cures, you will have no idea what the properties of the cured resin are.
|
|
|
|
|
dcfoster
|
|
|
Group: Forum Members
Posts: 32,
Visits: 100
|
My previous post had a question about mixing different brand epoxy resins with different epoxy hardeners. Anyone know if you can mix one brand with another? I would assume if you can that its contingent upon what the makeup is of each. But how would I know what to look for?
|
|
|
|
|
dcfoster
|
|
|
Group: Forum Members
Posts: 32,
Visits: 100
|
Well the part needed alittle repair. While I was pulling vacuum a thin wall in the mould broke and was pulling air from the underside. I used gum tape and fixed the issue. Still had some dry spots where very little resin was on the fiber. But I was able to mostly repair it, got a lot of compliments from folks at the car show so hopefully I can really do better when I redo all the parts. Gonna really take time on the moulds next go as well make sure the flange is larger so I have more wiggle room. One question, can u mix different hardeners with different resins? I want to mix west systems 207 ultra clear hardener with dura-klears epoxy. The 207 has a longer pot life than the standard hardener for dura-klear. Thank you again with all the help so far you all have really advanced me miles ahead of where I would be had I just tried to google and read stuff and figure it out myself.
|
|
|
|
|
dcfoster
|
|
|
Group: Forum Members
Posts: 32,
Visits: 100
|
I have a flow control lever, just was so surprised at the radical difference in flow rate that it caught me off guard
|
|
|
|
|
Shaneer22
|
|
|
Group: Forum Members
Posts: 156,
Visits: 14K
|
Also slow down your infusion using the clamps,it helps especially on small parts.
|
|
|
|
|
dcfoster
|
|
|
Group: Forum Members
Posts: 32,
Visits: 100
|
So I did infusion again, but this time I ran the feed line the length of the part. Holy crap it went so fast I wasnt even prepared for it. I thought I mixed enough resin but ended up pulling some air into the line before I had a chance to clamp it off. Hopefully this will work out. while I was going through the sanding to fix the mould I found this thing has bubbles everywhere. That fiberglass resin was so bad. Im deffinately going to make a new mould. I was able to get the room upto 80 degrees F so hopefully I can help it cure marginally faster otherwise im going to demould around 6pm and that doesnt leave me much time to fix potential issues and to trim.
|
|
|
|
|
dcfoster
|
|
|
Group: Forum Members
Posts: 32,
Visits: 100
|
Here are some pics of the part and the data sheet of the resin |
|
|
|
|
Hanaldo
|
|
|
Group: Forum Members
Posts: 2.5K,
Visits: 28K
|
Can you post a photo of the infused part that failed? Might give an indicator as to whether there is any point trying to infuse with the mentioned corrections. The way you described the bagging process is pretty much it, except I prefer to wet out the fabric AFTER placing it in the mould. Less mess, and handling wetted fabric is a real nightmare. So basically, apply mould release, brush resin into mould, lay in first layer of fabric and stipple it with your brush to draw the resin that you applied to the mould surface through the fabric. This helps to reduce air bubbles. When you have drawn up as much of that resin as you can, apply more resin to the top. You want your first layer to be quite resin rich, so apply a bit more than it needs. Then repeat the process with the second and third layers, and finally the peel ply. Then bag, making sure there is no bridging anywhere as you pull the bag down. I recommend running the pump for 2 hours or so, just to give the resin a chance to go off. You can clamp it off and turn the pump off as soon as you have got full vacuum if you like, but then if you have a leak you will return to find a ruined part. Better to keep the vacuum running as long as you can. Leave it bagged for 24 hours ideally, but check your resin data sheet for demould time.
You are also going to want to get everything ready BEFORE you mix your resin. So have your release agent applied for the correct amount of time (preferably do this the day before, but a couple of hours after your last coat will suffice) fabric cut, your brush ready, and all your vacuum bagging stuff cut and read to go as soon as you have laid up the part. With a 17 minute pot life, you really need to make sure you are well organised and don't waste any time doing stuff that you could have had ready before you started.
For wet lay, you want a 50/50 ratio. So if you have 3 layers of carbon weighing 8oz, then you need 8oz of resin. Realistically, mix up 10-15% more to allow for wastage.
The resin I use for infusion is 400cps, and that is on the thick side. The infusion specific resin I have here is 220cps. So 600cps is too thick and quite likely won't wet out the fibres properly.
|
|
|
|
|
ChrisR
|
|
|
Group: Forum Members
Posts: 363,
Visits: 3K
|
Just read the last sentence, if you are going to infuse - weigh everything that will get resin on it, fabric, peel ply, infusion mesh; work on a 50/50 fibre/resin ratio so if you weigh 4oz total then use 4oz resin (at least) you may want to work on a 40/60 fibre/resin to get a nicer finish. Also measure the length of the infusion hose(s), calc the volume and convert that to weight, plus a bit for each pot. Add them all up and that's how much resin you need
|
|
|
|