Author Topic: Damn putty seems to have expanded. (Read 3689 times)

Bones · « **on:** October 05, 2005, 07:19:19 pm »

After sealing my MDF cab with three coats of sealer and sanding the finish between each coat, I was then left with a smooth clean perfect surface that felt like glass and an eager anticipation to splash on some undercoat followed by orange colour

Bumblebounces · « **Reply #1 on:** October 05, 2005, 09:14:31 pm »

What kind of "putty" are you using? My experience with most filler products has been that if they are going to do something, they are going to shrink, not expand. And if they do shrink, it's usually during the initial curing process which you said should have been done long ago.

Hmmmmm. What are you sealing with? The only thing I can think of is that the filler is reacting to the sealer product. I share in your frustration of what to do now. It seems likely that if you work towards fixing it, this will just happen again. Sorry, I don't have any ideas for you, but please lets us know what you do and if it fixes the problem.

Bumble

Bones · « **Reply #2 on:** October 05, 2005, 09:50:38 pm »

Quote from: Bumblebounces on October 05, 2005, 09:14:31 pm

The only thing I can think of is that the filler is reacting to the sealer product.

Now there is a thought.... I am using a waterbased putty and perhaps it did absorb some moisture from the sealer. Seems strange it didn't swell with the first coats of sealer I applied some weeks ago but this seems like a reasonable explanation.....

Minwah · « **Reply #3 on:** October 06, 2005, 06:55:26 am »

This exact problem happened to me too. As Bumble says I was expecting it to shrink if anything...but some of my filled holes (I also spent a long time sanding back to perfectly smooth) raised up in some cases probably as much as 2mm.

I've rubbed all mine back to smooth, and have covered all areas possible with black vinyl. For the sides I'm just going to apply artwork over the top...not sure if I should paint it or not (something tells me I should, but I can't really be bothered).

In hindsight I would probably recommend using car body filler - it dries really quick and is not water based, plus is makes a really good smooth finish when sanded. I used 'P38' body filler for my control panels where I've filled in around my trackball mounting plate etc. and it worked really well.

Edit: Just thought I'd add that since I've sanded the problem filler back down 'smooth', it seems to be fine. I have no idea what caused the problem in the first place. My cabinet was in a cold damp garage when I filled it so I put it down to absorbing moisture from the air...

Bones · « **Reply #4 on:** October 06, 2005, 07:13:46 am »

Quote from: Minwah on October 06, 2005, 06:55:26 am

Edit: Just thought I'd add that since I've sanded the problem filler back down 'smooth', it seems to be fine. I have no idea what caused the problem in the first place. My cabinet was in a cold damp garage when I filled it so I put it down to absorbing moisture from the air...

This is what I wanted to hear. Reassurance! My cabinet is also exposed somewhat living in an open garage.... Very interesting.

Minwah · « **Reply #5 on:** October 06, 2005, 07:49:56 am »

Quote from: BrokenBones on October 06, 2005, 07:13:46 am

My cabinet is also exposed somewhat living in an open garage.... Very interesting.

Your Aussie garage is probably a bit more hospitable than the one I was using in English winter!

Good luck with putting it right anyway...

mahuti · « **Reply #6 on:** October 07, 2005, 04:06:33 pm »

Learning to use Bondo is a very valuable skill. It's pretty easy to use actually, and man does it have some strength. As long as it can get good contact.. it's super resillient.

I had to rebuild large missing chunks on my old cabinet, and the stuff worked fantasitic.

Ed_McCarron · « **Reply #7 on:** October 07, 2005, 05:40:09 pm »

I just bondo'ed the screw holes in my last cabinet. It was 3/4 MDF, 6 or 7 coats of paint by the time all was said and done.

Over the course of a few weeks, the bondo plugs lifted out a bit - maybe 1-2 mmm and are now visible.

The cab was in a climate controlled, not too humid childs playroom.

Whats that do to the theories?

Bones · « **Reply #8 on:** October 07, 2005, 06:51:16 pm »

Well I just re-sanded a couple. They smoothed out very easy, only took about 20 seconds for each one. I will keep going and put another coat of sealer over everything and leave it a week.

I will advise what happens and if they "bubble" again I will have to look at different options.

Freeplay · « **Reply #9 on:** October 08, 2005, 05:54:55 am »

Bones... i'd say its all the rain we have had the last couple of weeks

Mr. Bubblehead · « **Reply #10 on:** October 09, 2005, 06:22:13 am »

Water-based fillers can absorb moisture and expand due to a rise in humidity or when something is applied over them. The best solution has already been mentioned, use an epoxy-type filler such as Bondo or fiberglass.

Bones · « **Reply #11 on:** October 10, 2005, 07:19:09 am »

So on the weekend I sanded everything flat again and tonight went to prime the surface and whatya' know, I got raised bit's of putty again.

There was about 10 spots that I re-sanded and I have now applied another two coats of sealer so I suppose now it's a waiting game....

I am as close to smashing this thing as ---steaming pile of meadow muffin--- is to swearing.

Mr. Bubblehead · « **Reply #12 on:** October 10, 2005, 10:07:47 am »

Quote from: BrokenBones on October 10, 2005, 07:19:09 am

So on the weekend I sanded everything flat again and tonight went to prime the surface and whatya' know, I got raised bit's of putty again.

There was about 10 spots that I re-sanded and I have now applied another two coats of sealer so I suppose now it's a waiting game....

I am as close to smashing this thing as ---auto-censored--- is to swearing.

You may have trapped some moisture underneath there?? if it keeps raising up now it will probably do it again after the paint is applied. If it were me, I would take the time to scrape out the putty and use an epoxy filler.

Minwah · « **Reply #13 on:** October 10, 2005, 10:19:05 am »

Quote from: Mr. Bubblehead on October 10, 2005, 10:07:47 am

You may have trapped some moisture underneath there?? if it keeps raising up now it will probably do it again after the paint is applied. If it were me, I would take the time to scrape out the putty and use an epoxy filler.

I must admit I'm considering doing this. Don't really want to but on the other hand I don't want the filler to raise/move after I have applied the side art.

jcrouse · « **Reply #14 on:** October 10, 2005, 10:23:23 am »

One word: Laminate!

John

Minwah · « **Reply #15 on:** October 10, 2005, 10:28:28 am »

Quote from: jcrouse on October 10, 2005, 10:23:23 am

One word: Laminate!

How easy is this? I would think it would be a pain without lying the cab down. Also how thick is it?

Flinkly · « **Reply #16 on:** October 10, 2005, 10:36:09 am »

it would be very difficult without laying the cabinet down. you just get a big enough sheet of laminate to cover both sides, rough cut it to abuot an inch oversized, glue both sides, wait for tackiness, and throw them together. of course you want to watch out for air bubles. after it dries, you go around the outside with a flush trim router bit and your golden (just in case, "golden" is an american term for...done, i guess).

jcrouse · « **Reply #17 on:** October 10, 2005, 10:36:54 am »

To add it to an existing cabinet would be pretty simple IF you had smooth sides. Yes you would have to lay the cabinet on it's side for ease of installation and trimming. The main problem is the cost. a 4' x 8' sheet here is about (average) $50 US. The thickness varies depending on the grade. The standard grade is about .045. I use 5/8" MDF and 3/4" T molding and then trim the T Molding to size.

John

Minwah · « **Reply #18 on:** October 10, 2005, 11:54:29 am »

Hmm I think I'll just stick with covering the sides with vinyl. I'm going to get a quote for the signwriter style computer-cut vinyl for my sideart. Hopefully this will be a lot cheaper than having the whole lot printed,

Havok · « **Reply #19 on:** October 10, 2005, 12:14:23 pm »

Quote from: BrokenBones on October 10, 2005, 07:19:09 am

So on the weekend I sanded everything flat again and tonight went to prime the surface and whatya' know, I got raised bit's of putty again.

Wade · « **Reply #20 on:** October 10, 2005, 01:22:51 pm »

This is another reason why I encourage people not to screw their game together from the outside. Screw it from the inside, glue it inside, and use a few carriage bolts if needed to support key areas.

It isn't just to avoid having to fill and sand. It is because filler and wood don't have exactly the same properties, and with enough change in temperature or moisture, the filled areas are likely to be noticable.

Every real video game I have except ONE, has carriage bolt heads exposed on the outside. So what's the big deal with having a couple for the monitor and the base in a home-built cabinet?

Wade

Minwah · « **Reply #21 on:** October 10, 2005, 01:56:31 pm »

Quote from: Wade on October 10, 2005, 01:22:51 pm

This is another reason why I encourage people not to screw their game together from the outside. Screw it from the inside, glue it inside, and use a few carriage bolts if needed to support key areas.

It is a fair point, but I don't like screwing from the inside as it isn't as strong. Granted with carriage bolts as you suggest it would be OK but not quite as nice to look at. I admit I'm a hypocrite as I actually like seeing the bolts on control panels!

I think filler is ok to use, but my lack of experience (& possibly the same goes for others) means I messed it up a bit. Something learned anyway...

Havok · « **Reply #22 on:** October 10, 2005, 02:02:52 pm »

Glue is always stronger than screws. There really is no reason to use screws at all. Glue, clamp, let dry and you're all done!

Minwah · « **Reply #23 on:** October 10, 2005, 02:19:09 pm »

Quote from: Havok on October 10, 2005, 02:02:52 pm

Glue is always stronger than screws. There really is no reason to use screws at all. Glue, clamp, let dry and you're all done!

I glued & screwed. Glue is very strong but I messed up a few parts of my cab and managed to break the glued bits apart (fortunately). You couldn't break a screwed cab apart without a screwdriver...

daywane · « **Reply #24 on:** October 10, 2005, 07:02:13 pm »

Quote from: Havok on October 10, 2005, 02:02:52 pm

Glue is always stronger than screws. There really is no reason to use screws at all. Glue, clamp, let dry and you're all done!

you may be right, but I hill have to say, that needs to be proven to me.

Flinkly · « **Reply #25 on:** October 10, 2005, 07:39:25 pm »

a glue joint is strong, but just gluing together a structure isn't as strong as just screwing. the glue joint isn't really the problem, it's the rest of the wood, it isn't as strong. a screw going from the outside in clamps it all together, not just that small space between each piece.

sorry for the info, i'm not only a woodworker but a studying engineer.

Bones · « **Reply #26 on:** October 11, 2005, 02:37:06 am »

There is no way I could bring myself to sit a heavy expensive monitor on a shelf that was not supported by a stack of big-ass screws as well as glue. I am sure it's just my perception of what's really strong, but I need to know there is metal in there.

Havok · « **Reply #27 on:** October 11, 2005, 10:36:56 am »

Quote from: Flinkly on October 10, 2005, 07:39:25 pm

a glue joint is strong, but just gluing together a structure isn't as strong as just screwing.

nostrebor · « **Reply #28 on:** October 11, 2005, 10:52:43 am »

Has anyone seen the photos of the moon patrol cabinet holding up the building? That cabinet was built using glue and dado joints.

I have had no problems with putty, because I used no screws through the outside of my cabinets. One has been moved at least 20 times... ZERO problems.

Minwah · « **Reply #29 on:** October 11, 2005, 10:53:27 am »

Quote from: Havok on October 11, 2005, 10:36:56 am

I've talked with professional woodworkers, and glue is all you need. Of course, you don't just glue wood at 90 degree angles: you dovetail, route, etc and glue. I would put that up against any 90 degree screw\glue setup you have for strength and reliability.

Oh I don't deny that. But doing decent wood joints is not easy for everyone (especially me)...anyone can glue & screw.

Wade · « **Reply #30 on:** October 11, 2005, 11:19:23 am »

I wouldn't say glue is "all you need". You need a very nicely made JOINT, PLUS glue. Glue is only half of the equation.

For 95% of us... it is far easier to glue and staple/screw strips on the inside of the cabinet. I do a fair amount of woodworking and I wouldn't consider making anything fancier.

Wade

Havok · « **Reply #31 on:** October 11, 2005, 12:16:56 pm »

Actually, if I were to say a blanket statement about fastening, I would have to say Duct Tape is all you need!

I dare anyone to disagree!!!

Abomination · « **Reply #32 on:** October 11, 2005, 08:49:31 pm »

Quote from: Havok on October 11, 2005, 12:16:56 pm

Actually, if I were to say a blanket statement about fastening, I would have to say Duct Tape is all you need!

I dare anyone to disagree!!!

I once saw military grade duct tape used to hold the front end of a hummer, that was half torn off from a land mine, together for over 50 miles through rough desert terrain at 60mph+ without giving out. Seen it used as bandages, boot repairs, patch holes in airplanes (don't ask), I saw a guy tape one strip to one side of a door and one to another letting it meet in the middle, used that as a hinge for the door (normal heavy wood door) for months... That stuff is amazing and one of the more usefull things that the military invented.

Bones · « **Reply #33 on:** October 12, 2005, 07:11:17 am »

That duct tape is definitely strong stuff. They hold damaged panels in place on the Australian V8 supercars and these do close on 300km/h.

Putty update.
Recent coats of sealer have now been on 2 days and no imperfections are noticeable as yet.....

PetitMorte · « **Reply #34 on:** October 12, 2005, 02:01:28 pm »

The gorilla Glue people have expanded their product line and are now offering "Gorilla Tape".

Give the stuff props for *sticking* to a brick.

Flinkly · « **Reply #35 on:** October 12, 2005, 02:11:53 pm »

supposively in the military they use their special duct tape to cover bullet holes in aircraft, among other vehicles. if you trust tape that well, it's gotta be good.

anyways, i am very interested at the true thread here, cause i've got some holes to putty too.

so is the plan to putty, prime, sand and then prime again in hopes that it won't grow anymore? let's hope it works...

Bones · « **Reply #36 on:** October 17, 2005, 06:33:48 am »

I have now applied the first two coats of colour over the top of a tinted undercoat, which was painted onto the MDF sealer.

The bumps have not returned.

I still am not convinced of what was responsible for the problems I had, but it appears I am now victorious. (With the exception of the colour which is earning its share of criticism.....

)

Thanks for all the input.

Stingray · « **Reply #37 on:** October 18, 2005, 04:45:02 pm »

I like the color if it makes ya feel any better, Bones.

-S

pcates · « **Reply #38 on:** October 19, 2005, 11:06:54 pm »

Color looks like Donkey Kong Jr orange.....not bad if you like orange


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