Is Acetone Necessary

[ddrieck]

Hey all,
I'm getting ready to do some fiberglass work on my latest project boat. I will be using waxed fiberglass resin due to having gotten 5 gallons free from a former co-worker whom just finished his project boat. The resin is new and unopened with a manufacture date of May-1-09.

I know I need to grind in between coats but is Acetone necessary before the next coat or can I use mineral spirits? Reason I ask is because I have 5 gallons of the mineral spirits on hand.

Any thoughts??

 

[boatflipper]

Re: Is Acetone Necessary

I dont see why paint thinner wouldn't work if all that is needed is a clean surface. I used acetone on my deck but that was only because I had used it to thin the resin I applied to my deck before laying down cloth.

 

[Spinnaker]

Re: Is Acetone Necessary

You need acetone regardless. I wouldn't use mineral spirits.

 

[ondarvr]

Re: Is Acetone Necessary

Clean it off first with whatever solvent you want, then grind it, clean up the dust with a broom or shop vac and then glass it, but like Sp said, you're going to need some acetone eventually.

The easier method is time your work so that the first layup isn't cured before you do any overlaps, can't always be done that way though.

 

[ddrieck]

Re: Is Acetone Necessary

Clean it off first with whatever solvent you want, then grind it, clean up the dust with a broom or shop vac and then glass it, but like Sp said, you're going to need some acetone eventually.

So just what exactly is the acetone, thinning? the mixture?

If I clean the surface with mineral spirits, grind, vacuum, and then glass the next layer....where does the acetone come into play besides thinning the resin?

 

[ondarvr]

Re: Is Acetone Necessary

So just what exactly is the acetone, thinning? the mixture?

If I clean the surface with mineral spirits, grind, vacuum, and then glass the next layer....where does the acetone come into play besides thinning the resin?

It cleans all the sticky goo off you and the tools.

 

[Bondo]

Re: Is Acetone Necessary

It cleans all the sticky goo off you and the tools.

Reason I ask is because I have 5 gallons of the mineral spirits on hand.

Ayuh,... And 500 gallons of Mineral Spirits won't help abit...
It don't cut raw poly resin, at All, as far as I could ever see...

The reason they make sooo many solvents is because you need the Right 1s for the base materials you're usin'....

 

[backlashed]

Re: Is Acetone Necessary

I've found out the hard way to many times that you should use what is recommended. Don't let a relatively inexpensive compatibility question ruin your day.
If you want to use it for general prep clean up, wipe a piece of glass with it, and let it dry. If it doesn't leave a film on it, it's probably OK. If it does, DON"T use it, you will contaminate the surface.

 

[Spinnaker]

Re: Is Acetone Necessary

Also Acetone is not for thinning. It breaks down the resin or gel. Styrene is for thinning. The only real time you'll use styrene is thinning gel for spraying.

 

[ddrieck]

Re: Is Acetone Necessary

Ok...just so I have it straight in my head...no mineral spirits and glass as follow:


1. grind, vacuum, and acetone surface to be glassed
2. Layout and wet in 1st layer
3. Grind, vacuum, and acetone
4. Layout and wet in 2nd layer
5. Grind, vacuum, and acetone

.....repeat if more glass layers are needed.

Is this correct??

 

[Spinnaker]

Re: Is Acetone Necessary

You don't have to let each layer kick. Put your layer of mat on, air roll, then your next layer, air roll.

 

[osborn159]

Re: Is Acetone Necessary

i think what spin is saying is dont use quite as much catalyst in your mix, giving you more time to work it, if it does harden, ie you cant ding it w/ your finger nail i think youll have to grind, do not use to little catalyst or it may not react and cure

 

[ondarvr]

Re: Is Acetone Necessary

What he's saying is that there is no need to wait between layers, multiple layers can be put down at one time.

Depending on the resin, ambient temperature and weight of glass, you can normally put on 3 to 4 layers at one time without any issues. Some resin cures too fast and the temps may be too high at times and if you have a very heavy glass it may not be possible, but 2 to 3 layers of 1.5 OZ mat is easy.

Most of the time you would be using mat and a woven, or stitched fabric together, a mat, roving, mat, roving layup is quick and easy.

 

[osborn159]

Re: Is Acetone Necessary

ondarvr, remember most of us dont have the experience and time with these products you and spin obviously have, do you think someone with minimal experience and tooling is going to be able to lay 2-3 plys, even on a transom in a 14' jonboat in 75deg weather would be difficult before its starting to gel. thats why i work small areas with 1% catalyst mix to give myself more time.
i dont have a wetting table or some of the other equipment you may have, wish i did, would make life easier, not cost effective for rehabing 1 boat.
i do appreciate all your advice and the help you provide, do not misinterpret my comments, you have been very helpful to me answering some of my inexperienced ???s

 

[ondarvr]

Re: Is Acetone Necessary

I know what you're saying, it seems difficult to imagine doing large or multiple layer layups quickly. Many people make the mistake of fiddling with the glass and then are slow to wet it out.

On a flat surface just dump the resin on and move it around with a fuzzy paint roller as needed, mixing a gallon at a time and using it up before it gels isn't that hard doing it this way. When using roving, cloth or stitched products it can go even faster because there is far less rolling. The woven or stitch fabric is always the top layer and you can just squeegee (plastic bondo spreader will work) about 90% of it, the edges get rolled and/or brushed if needed

Like I said before, you can't always do it like this because of ambient conditions, but this time of year it works well.

 

[ddrieck]

Re: Is Acetone Necessary

Thanks for all the help and advise.....

The area I needed to glass in was a 2' x 8' section I removed that the ski locker door sits in. Was mushy in spots due to a the PO cutting in a few bass boat seat bases and didn't realize there was no support under the deck in that area.

I mixed up 1/2 gallon and was able to get down 3 layers off woolven mat before it started to kick. Outside temp was 43 degrees and I leaned off the hardener a bit to have more time to wet things out. Worked like a charm and had about 25 minutes of pot life. Had all the glass cut and ready to go before starting and the Wife handed it to me as I needed it. Used a small foam paint roller to spread the resin around after just pouring it from the pale onto the deck. I used one of the wife's old spatulas to help remove any air bubbles as I didn't have one of the bondo squeegees.

Was able to get the entire top deck and seems glassed in and ready for carpet tomorrow.

 

[ondarvr]

Re: Is Acetone Necessary

Sounds like it went well, good job.

 

[osborn159]

Re: Is Acetone Necessary

ondarvr,so im probly a little intimidated working small, i'll give it a try this way and see how it works.
thanks again,
D

 

[pete44]

Re: Is Acetone Necessary

Hey all,
I will be using waxed fiberglass resin due to having gotten 5 gallons free from a former co-worker whom just finished his project boat. The resin is new and unopened with a manufacture date of May-1-09.

Does'nt poly resin have a "shelf life"? (opened or unopened)...Where epoxy resin does not..And also a "waxed" resin requires sanding where an "unwaxed" does not?...I may go with this product (rot doctor)..look at their research..more $$$ BUT...I do not want to do this again...Here is their link....Just my thoughts...Great to get FREE stuff from anyone though! ....Maybe someone else can comment on rot doctor products....

http://www.rotdoctor.com/


Pete

 

[Bondo]

Re: Is Acetone Necessary

Ayuh,.. Rot Doctor is nothing but Thinned epoxy....
It's Way cheaper to thin your own...