Dull polish using Clear Cast Alumilite

[Doug Goldberg]

I have been using Alumilite Clear very successfully polishing with conventional sandpaper up to 600, wet/dry sandpaper up to 1500 and then wet micromesh pads up to 12,000. The finish has been flawless. As of late the finish is dull at best with sanding marks still in the tube. I have used blanks cured on the benchtop and in a pressure pot as well with the same result. The uncured resin is at least 9 months old and has been stored in my garage which is in Florida. I have not tried new resin yet but am thinking the resin got too old. Your thoughts? Thanks in advance. Doug

 

[JohnU]

It's very possible that your resin is getting old, being that you live in a humid and hot climate. The problem with urethane resin is you work very hard to get a shiny clear finish but with normal use it dulls. I now apply a GluBoost flexible finish, which shines up very easily (easier than naked urethane resin) and holds up very well with normal use. Might be what you need to fix your current issue.

 

[Hippie3180]

It's very possible that your resin is getting old, being that you live in a humid and hot climate. The problem with urethane resin is you work very hard to get a shiny clear finish but with normal use it dulls. I now apply a GluBoost flexible finish, which shines up very easily (easier than naked urethane resin) and holds up very well with normal use. Might be what you need to fix your current issue.

Not to take over this thread, but when I try to use Gluboost on Alumilite I get swirl marks from application. Any tips for this?

 

[Doug Goldberg]

It's very possible that your resin is getting old, being that you live in a humid and hot climate. The problem with urethane resin is you work very hard to get a shiny clear finish but with normal use it dulls. I now apply a GluBoost flexible finish, which shines up very easily (easier than naked urethane resin) and holds up very well with normal use. Might be what you need to fix your current issue.

Thanks John. I'm new to casting. Can you suggest a different resin that will give easier more consistent results?

 

[walshjp17]

Just to be clear, the headline to your post says "Clear Cast Alumilite". The text of your post says "Alumilite Clear". Clear Cast and Clear are two different products. Clear Cast is Epoxy while Clear and Clear Slow are urethanes. You also note that you cure on the benchtop and in a pressure pot. Epoxies can be cured with out a pressure pot while urethanes definitely need the pot. So, which one are you using?

 

[Doug Goldberg]

Just to be clear, the headline to your post says "Clear Cast Alumilite". The text of your post says "Alumilite Clear". Clear Cast and Clear are two different products. Clear Cast is Epoxy while Clear and Clear Slow are urethanes. You also note that you cure on the benchtop and in a pressure pot. Epoxies can be cured with out a pressure pot while urethanes definitely need the pot. So, which one are you using?

I am using Alumilite Clear Cast Epoxy. I'm rapidly gaining an appreciation for the subtle differences in Alumilite's products

 

[JohnU]

I believe every resin has its purpose. One is not better than the others, there are just better applications for each. Alumilite Clear and Clear Slow are urethane resins. I like them for embedded object, labels and color casts. They are also very durable for kitless and threads.

Silmar 41 is a polyester resin. It's great for snakeskins, carbon fibers, layered pours and mica color casts.

Anything that starts with "Amazing" and the numerous other branded epoxies are good for just about everything only they usually take 7-10 days to fully cure from a flexible state. I'm not a big epoxy user. They are also very hard on your reusable molds.

I apply thin ca first (red label Gluboost) as a scratch filler from sanding. Then I use the orange label and layer 3-4 coats with the lathe on at a vey low speed. I lightly sand with 600 grit to knock down any high spots or ridges from application. Then I turn the lathe on high and use extra fine 0000 steel wool, before switching to micro mesh (wet sanding). I finish with a polish and clean rag. Works great every time.

 

[Doug Goldberg]

I believe every resin has its purpose. One is not better than the others, there are just better applications for each. Alumilite Clear and Clear Slow are urethane resins. I like them for embedded object, labels and color casts. They are also very durable for kitless and threads.

Silmar 41 is a polyester resin. It's great for snakeskins, carbon fibers, layered pours and mica color casts.

Anything that starts with "Amazing" and the numerous other branded epoxies are good for just about everything only they usually take 7-10 days to fully cure from a flexible state. I'm not a big epoxy user. They are also very hard on your reusable molds.

I apply thin ca first (red label Gluboost) as a scratch filler from sanding. Then I use the orange label and layer 3-4 coats with the lathe on at a vey low speed. I lightly sand with 600 grit to knock down any high spots or ridges from application. Then I turn the lathe on high and use extra fine 0000 steel wool, before switching to micro mesh (wet sanding). I finish with a polish and clean rag. Works great every time.

Really helpful. Thanks for taking the time to help me.
Doug

 

[its_virgil]

The Alumilite epoxy is actually Alumilite Amazing Clear Cast and Amazing Clear Cast Plus

 

[jrista]

Not to take over this thread, but when I try to use Gluboost on Alumilite I get swirl marks from application. Any tips for this?

I've been going through GluBoost trials myself lately. I'm curious how you are applying? What kind of applicator? Glue on the applicator? Or glue on the blank?

 

[JohnU]

I've been going through GluBoost trials myself lately. I'm curious how you are applying? What kind of applicator? Glue on the applicator? Or glue on the blank?

I roll up a piece of paper towel and flatten it. I'm using "Bounty" with the half sheets. I cut them in half so I'm only using a piece about 5" square. Rolled up it's about the size of a 1/4" dowel rod but I flatten it with my fingers before I use it. With the lathe on low I place 2-3 drops on the towel and lightly press and wipe it across the blank (while using delrin bushing). I spray Gludry lightly from about 8-10" away, wait a few seconds and apply the second coat. I like to use 3-5 coats depending on the material. If it's porous or not smooth I use the blue label thick fill and finish until the surface is smooth. For everything else I use the orange label. I also apply 2 coats of the red label first to fill any scratches.

I know some who like to rub it on the blank with the lathe off but I like the lathe on (low speed) as I apply it. I think I get a more even layer across the blank.

 

[Hippie3180]

I've been going through GluBoost trials myself lately. I'm curious how you are applying? What kind of applicator? Glue on the applicator? Or glue on the blank?

Like John U, I use paper towel cut into strips and folded. I use blue shop towels though. I apply it to the paper towel and then the blank. I've used it on wood with great success but get swirls on Alumilite. John U says he has his lathe turning very slowly, I'm going to try that next.

 

[jrista]

Like John U, I use paper towel cut into strips and folded. I use blue shop towels though. I apply it to the paper towel and then the blank. I've used it on wood with great success but get swirls on Alumilite. John U says he has his lathe turning very slowly, I'm going to try that next.

I get what I call "wrinkles" all the time, although with a slower lathe speed (~500rpm) they aren't as bad as they were at a higher speed (1000+).

I've never had a perfect finish just by applying gluboost to anything, though. I always have to sand it smooth first, then polish it, to get the perfect finish, no matter what I do or how nicely the glue applies. I suspect its the same with alumilite.

 

[JohnU]

Like Jrista mentioned, you may have to lightly sand with 400-600 grit after you apply your layers. There are usually slight ridges in the glue from application. Just knock them down without sanding through all the layers and then micro mesh or whatever your process is to get a glass like finish. The thinner the glue and its layer, the less ridges you will have to knock down. I would rather apply several thin layers than a couple thick ones.