bumps in fiberglass
Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=62112
Printed Date: May 15, 2024 at 6:52 PM
Topic: bumps in fiberglass
Posted By: bsinnest
Subject: bumps in fiberglass
Date Posted: August 26, 2005 at 8:54 PM
hey guys. haha, i am fiberglassin my door panels and i didn't put that much fiberglass on. and i did the bodyfill stage, but i screwed up somewhere. cause when i run my finger across the project i feel these bumps like the thing isn't that smooth at all. and i sanded it for a long time. it just seems like it is going to be impossible to have it all smooth. Any advice on this topic would help me alot. i mean even if you said to torch it or something lol. thanks guys
Replies:
Posted By: auex
Date Posted: August 26, 2005 at 9:26 PM
Sand, sand, sand, sand some more, sand, sand, sand even more, etc... Only thing you can do. Lightly spray it with black spray paint, don't coat just go over it and spot it with the paint, you will see the bumps when there is contrast.
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Posted By: bsinnest
Date Posted: August 26, 2005 at 11:21 PM
thanks. according to your bumps, i have a feeling that i have alot of sanding to do!. lol i'll get on it tomorrow, and i'll try that black paint thing, sounds good. i'll take pics of it when i am done. its a panel for a mazda mx3
Posted By: bsinnest
Date Posted: August 26, 2005 at 11:22 PM
according to your advice***
Posted By: abovestock
Date Posted: August 27, 2005 at 1:33 AM
I hope it is not like the old mustang trunk project with tons of Bondo lol. Use a paint stir stick with the sand paper to be sure that it is flat. This will help you sand faster and save time in do overs. Also sand your glass flat before you apply any body filler, and use a random orbital sander to cut down on time.
Posted By: bsinnest
Date Posted: August 27, 2005 at 10:43 AM
yea, i hope it isn't that bad either. its all i got for door panels lol. I'll keep on trying, but could you elaborate a litte more on the paint stir stick thing? cause its in a groove. and the random orbital sander does help alot. Thanks.
Posted By: abovestock
Date Posted: August 28, 2005 at 2:37 AM
I use this to block out cars. I don't see what you are doing so it is hard for me to picture. I take a paint stir stick and wrap sand paper around it to make sure what I am sanding comes out flat. If you sand just with your hand you get waves and bumps that form because of uneven pressure. If you can add some pictures so that we can better help you.
Posted By: darkknight1999
Date Posted: September 10, 2005 at 8:52 AM
You should get a sanding block or better yet an air sander if you have the cash. This will sand it without your fingers making marks in it. If you sand by hand you might be pressing to hard, and when you do that your leaving low spots in the finish because you don't have the same pressure inbetween your figers as you do at your fingertips. You can also use a high build primer to help fill in the low spots once to sand. Use a different color compared to whatever color your filler is so you can see the difference while you sand. ------------- -JOHN
www.rimotorsports.com
Posted By: Velocity Motors
Date Posted: September 10, 2005 at 9:35 AM
Here's what I would do ( listen up trade secret coming : ) Mix up another batch of bodyfiller and spread it on until smooth again. Take the courses sand paper you can get in a sanding block form and wait until the body filler is about 3/4 dry and start lightly sanding. The body filler will start pilling up and will roll off the peice in large rolls of body filler. This is what you want & you will probably need to remove the sand paper a couple of times because it will fill up with the body filler fast. Your project will be smooth, flat & bump free with this method.
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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: bsinnest
Date Posted: September 11, 2005 at 10:14 PM
that sounds like a good idea Velocity Motors, and i am going to attempt to do that as soon as i finish putting in the standard transmission and engine, (hopefully this week) then hopefully all works out that i can get that trick to work for me and have my panels smooth, what coarse sand paper grit would you prefer, like the 40-80 grit (automotive sand paper) or should i start in the 100's?
Thanks for the tips.
Brian.
Posted By: darkknight1999
Date Posted: September 11, 2005 at 10:21 PM
Yeah know Jeff I never thought to blend them together like that... That's a great idea!
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-JOHN
www.rimotorsports.com
Posted By: Velocity Motors
Date Posted: September 11, 2005 at 11:40 PM
bsinnest wrote:
that sounds like a good idea Velocity Motors, and i am going to attempt to do that as soon as i finish putting in the standard transmission and engine, (hopefully this week) then hopefully all works out that i can get that trick to work for me and have my panels smooth, what coarse sand paper grit would you prefer, like the 40-80 grit (automotive sand paper) or should i start in the 100's?
Thanks for the tips.
Brian.
I use 60 or 80 grit for this step. Just make suer that you don't wait too long for it to dry. If it starts creating dust when you sand, it's too late and you will need to sand for quite some time. The texture of the body filler should still be some what rubbery but not to the point where your first pass drags it right back to the last layer. The sand paper will fill instantly with body filler, but that's OK. Good luck and post your results. ------------- Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: Velocity Motors
Date Posted: September 11, 2005 at 11:42 PM
darkknight1999 wrote:
Yeah know Jeff I never thought to blend them together like that... That's a great idea!
I usually take about an hour off sanding for me when I do it this way. ------------- Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: realitycheck
Date Posted: September 12, 2005 at 7:44 AM
My new way of sanding, 4 1/2" grinder with a 60 grit flap disc on it. Must be very careful with this though one slip and its time to break out the resin again.
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Learning the trade one fiberglass creation at a time!
Posted By: Velocity Motors
Date Posted: September 12, 2005 at 9:45 AM
realitycheck wrote:
My new way of sanding, 4 1/2" grinder with a 60 grit flap disc on it. Must be very careful with this though one slip and its time to break out the resin again.
I did this once as well, the problem is on those curves or rises that you want to keep. I hardly use my DA sander any more since I learned this technique about 2 years ago. It's straight as an arrow and takes time off the project by at least 50 % ! Give it a shot the next time you use body filler. ------------- Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: realitycheck
Date Posted: September 12, 2005 at 1:05 PM
Jeff, tell me if this is what your saying do. You put a coat of filler on then you sand it before it gets hard so that it comes off in little chunks. Then you add more body filler and do this again? Is this right or am I confused? I think I am.
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Learning the trade one fiberglass creation at a time!
Posted By: showchic
Date Posted: September 23, 2005 at 10:40 AM
how about wet-sanding... juss a thought
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